?
Which activity is health enhancing?
folding a load of laundry
driving long distances
O biking to school
unloading the dishwasher
Answer:
biking to school
Explanation:
plato
In a sound wave, the wavelength is equivalent to the distance from a region of high pressure to the region of mean
pressure
True
False
On the image at right, the two magnets are the same. Which paper clip would be harder to remove?
Answer:B
Explanation: The book is thinner making magnets attraction stronger, making the paper clip harder to move
Which of the following phrases describes a motor?
A. Changes electrical energy to mechanical energy
B. Never used in appliances with moving parts
C. Can be powered by a hand crank
D. Does not use the interaction between a spinning coil of wire and a
magnet
Which of the following locations will be relatively warmer during summers, and why? A. An inland location, because water heats up faster than land.
B. A coastal location, because water heats up faster than land.
C. A coastal location, because water has higher specific heat than land.
D. An inland location, because land has lower specific heat than water.
For a research project, a student needs a solenoid that produces an interior magnetic field of 0.0300 T. She decides to use a current of 1.00 A and a wire 0.500 mm in diameter. She winds the solenoid in layers on an insulating form 1.00 cm in diameter and 10.0 cm long. Determine the number of layers of wire needed. (Round your answer up to the nearest integer.)
Answer:
121m
Explanation:
Magnetic field = 0.03
Current = 1.00A
Diameter = 0.5
Length = 10vm
B = UoIN/Lcylinder * n
n = number of layer
n = 0.5x10^-3 x 0.03/4pi x 10^-7 x 1
= 0.0005x0.03/12.56x10^-7
= 11.94
~12
Average radius
= 0.008
Length of wire = 2x3.13x0.008x12x200
= 120.6m
= 121m
A 0.300 kg ball, moving with a speed of 2.5 m/s, has a head-on collision with at 0.600 kg ball initially at rest. Assuming a perfectly elastic collision, what will be the velocity of the small ball if the heavier ball has a speed of 2m/s after collision.
Answer:
1.25 m/s
Explanation:
Given,
Mass of first ball=0.3 kg
Its speed before collision=2.5 m/s
Its speed after collision=2 m/s
Mass of second ball=0.6 kg
Momentum of 1st ball=mass of the ball*velocity
=0.3kg*2.5m/s
=0.75 kg m/s
Momentum of 2nd ball=mass of the ball*velocity
=0.6 kg*velocity of 2nd ball
Since the first ball undergoes head on collision with the second ball,
momentum of first ball=momentum of second ball
0.75 kg m/s=0.6 kg*velocity of 2nd ball
Velocity of 2nd ball=0.75 kg m/s ÷ 0.6 kg
=1.25 m/s
A 806 kg automobile is sliding on an icy street. It collides with a parked car which has a mass of 682 kg. The two cars lock up and slide together with a speed of 23.1 km/h. What was the speed of the first car just before the collision?
Answer:
42.6km/h
Explanation:
Step one:
given data
mass of the first car M1= 806kg
the velocity of the first car V1=?
mass of the second car mass M2=682kg
velocity of the second car V2= 0km/h -----Note the car is parked
common velocity V=23.1km/h------Note: the two cars have common velocity
since the collision is inelastic:
Step two:
Required:
The velocity of the moving car
We know that the expression for the conservation of linear momentum for inelastic collision is given as
M1V1+M2V2=V(M1+M2)
substitute
806*V1+682*0=23.1(806+682)
806V1+0=23.1(1488)
806V1=34372.8
V1=34372.8/806
V1=42.6km/h
The speed of the first car just before the collision is 42.6km/h
What are the things being compared in the following argument?
"The United Nations failed to intervene in Bosnia to prevent massive human rights violations and ethnic cleansing. It also failed to act to stop the murders of close to a million innocent people in Rwanda. THe UN will not intervene to stop any widespread slaughter of innocents in Nigeria."
a.
Ethnic cleansing in Nigeria and Bosnia
b.
The slaughter of innocents by the UN
c.
situations in which the United Nations might intervene
d.
Human rights violations in Rwanda and Bosnia
Answer:
C
Explanation:
The thing that is being compared in the given argument is Ethnic cleansing in Bosnia. The correct option is A.
What is Ethnic cleansing?Ethnic cleansing is the systematic removal of ethnic, racial, and religious groups from a given area with the goal of ethnically homogenizing the region.
In this group of resettled Bosnian refugees, ethnic cleansing has resulted in high rates of PTSD and depression, as well as other forms of psychological morbidity.
The long-term consequences of ethnic cleansing as a form of mass psychological trauma have yet to be studied.
Political elites seek to gain and/or consolidate political power by capitalizing on nationalism and the desire to create the domestic "other" in order to foster solidarity among the dominant nationality.
The topic under discussion in this argument is ethnic cleansing in Bosnia.
Thus, the correct option is A.
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A student wants to determine the coefficient of static friction μ between a block of wood and an adjustable inclined plane. Of the following, the minimum additional equipment the student needs to determine a value for μ is
Answer:
A protractor to measure the angle of the inclined plane with the horizontal
Explanation:
The student needs to lift the free end of the adjustable inclined plane until the object barely starts sliding, and measure the angle at which such happens. At that point, the force of friction equals the component of the weight in the direction of the incline. That is:
[tex]f=\mu\,* N = \mu * m g\, cos(\theta)[/tex]
and [tex]w_{//}= m\,g\,sin(\theta)[/tex]
Then
[tex]f = w_{//}\\\mu *\,m \,g\,cos(\theta) = m\,g\,sin(\theta)\\\mu = tan(\theta)[/tex]
and therefore, the coefficient of static friction is fully determined just by calculating the tangent of the angle that the incline forms with the horizontal.
Then the only extra instrument needed is a protractor to measure the angle.
A radio signal has a frequency of 1.023 x 108 HZ. If the speed of the signal in air is 2.997 x 108m/s, what is the wavelength of the signals? а 7.15 m b 5.23 m C 2.93 m d 0.93 m
Answer:
2.93 m (which agrees with answer "C" on the list)
Explanation:
Recall that the speed of the wave equals the product of the wave's length times its frequency. Therefore, the wavelength is going to be the quotient of the speed of the signal divided its frequency:
Wavelength = 2.997 10^8 / 1.023 10^8 = 2.93 m
Skier pushes him self along the snow on flat ground he feels Erizo cents on his body which way
Answer:
Forward
Explanation:
Since the skier pushes himself along the snow on flat ground and he feels air resistance, he will only feels air resistance when he starts moving (unless wind is blowing in opposite direction). The net force vector is dependent on the amount of force applied by the skier here we assume that skier continues to move in forward direction. The net force vector will act in the direction of acceleration, since the skier continues to move in the forward direction, therefore the net force vector will also point in the forward direction.
In a control system, an accelerometer consists of a 4.63-g object sliding on a calibrated horizontal rail. A low-mass spring attaches the object to a flange at one end of the rail. Grease on the rail makes static friction negligible, but rapidly damps out vibrations of the sliding object. When subject to a steady acceleration of 0.832g, the object should be at a location 0.450 cm away from its equilibrium position.
Required:
Find the force constant of the spring required for the calibration to be correct.
Answer:
8.4 N/m
Explanation:
m = Mass of block = 4.63 gm
g = Acceleration due to gravity = [tex]9.81\ \text{m/s}^2[/tex]
x = Displacement of spring = 0.45 cm
a = Acceleration of subject = 0.832g
k = Spring constant
Force is given by
[tex]F=ma[/tex]
From Hooke's law
[tex]F=kx[/tex]
So
[tex]ma=kx\\\Rightarrow k=\dfrac{ma}{x}\\\Rightarrow k=\dfrac{4.63\times 10^{-3}\times 0.832\times 9.81}{0.45\times 10^{-2}}\\\Rightarrow k=8.4\ \text{N/m}[/tex]
The force constant of the spring is 8.4 N/m.
The statement "46 m, East" refers to the ______________ of an object.
velocity
distance
displacement
speed
acceleration
Answer:
Distance
Example:
Answer:
Displacement
Explanation:
displacement implies a vector quantity that expresses the distance (in a straight line) between the starting and finishing points. Hence, the statement "46 m, East" refers to a displacement of 46 m toward the East.
A 1200 N force acts on an object, resulting in an acceleration of 8.0 m/s2. What is the mass of the object?
Answer:
The answer is 150 kgExplanation:
The mass of the object can be found by using the formula
[tex]m = \frac{f}{a} \\ [/tex]
f is the force
a is the acceleration
From the question we have
[tex]m = \frac{1200}{8} \\ [/tex]
We have the final answer as
150 kgHope this helps you
A 7300N elevator is to be given an acceleration of 0.150g by connecting it to a cable of negligible weight wrapped around a turning cylindrical shaft.
If the shaft's diameter can be no larger than 12.0cm due to space limitations, what must be its minimum angular acceleration to provide the required acceleration of the elevator
Answer:
The value is [tex]\alpha = 24.5 \ rad/s^2[/tex]
Explanation:
From the question we are told that
The weight of the elevator is [tex]W = 7300 \ N[/tex]
The acceleration it is to be given is [tex]a = 0.150 \ g = 0.150 * 9.8 = 1.47 \ m/s^2[/tex]
The diameter of the shaft is [tex]d = 12.0 \ cm = 0.12 \ m[/tex]
Generally the radius is mathematically represented as
[tex]r = \frac{d}{2}[/tex]
=> [tex]r = \frac{0.12}{2}[/tex]
=> [tex]r = 0.06 \ m[/tex]
Generally the minimum angular acceleration is mathematically represented as
[tex]\alpha = \frac{a}{r}[/tex]
=> [tex]\alpha = \frac{1.47}{0.06}[/tex]
=> [tex]\alpha = 24.5 \ rad/s^2[/tex]
Test Due! Which statement is true?
The correct answer is C. Mercury and Mars have the same gravitational force
Explanation:
This chart compares the different features of two planets in our solar system (Mercury and Mars). In this chart, the only numerical value or feature that is the same for both planets is gravity because for both planets gravity is 1.7 m/s2. This implies the gravitational force or the force that attracts objects towards the center of the planet is the same or that objects are pulled with the same force in both planets. Moreover, this factor depends on others such as mass, density, among others.
What is the relevant similarity in the following argument?
"If a single cell, under appropriate conditions, becomes a person in the space of a few years, there can surely be no difficulty in understanding how, under appropriate conditions, a cell may, in the course of untold millions of years, give origin to the human race"
a.
The human race is composed of many humans in the same way a human is composed of many cells
b.
understanding human biology is difficult and understanding the existence of the human race is difficult
c.
both involve biological processes of great complexity taking place under “appropriate conditions” and commencing with a single cell
d.
a person starts from a single cell and an animal life starts from a single cell
1000 kg car takes travels on a circular track having radius 100 m with speed 10 m/s. What is the magnitude of the centripetal force acting on the car? *
A- 1 N
B- 100 N
C- 1000 N
D- 10000 N
Answer:
its a
Explanation:
when is thermal equilibrium achived between two identical objects
need help ASAP
Answer: When two objects in contact with each other are at different temperatures, they are said to be in thermal equilibrium.
Explanation: . When two objects not in contact with each other are at the same pressure, they are said to be in thermal equilibrium.
During a safety crash, a car impacts a solid concrete barrier and and comes to rest in 0.10s. In a second test, an identical car traveling at the same initial speed impacts a line of water barrels and comes to rest in 2.3s. During which test was the change in the momentum of the car the greatest?
a. It is the same for both cars.
b. The car that hits the concrete barrier.
c. The car that hits the water barrels
Answer:
The correct answer is C
Explanation:
Change is momentum can be described as the change in the product of mass and velocity of a body. Every moving object as a momentum and the higher the momentum of this object, the harder it is to stop. Impulse (a force), which is sometimes used to describe change in momentum can be described as the product as force multiplied by time.
From the description above, it can be deduced that an increase in impulse can lead to a greater change in momentum. And an increase in impulse can be brought about by an increase in the time it takes a body to be brought to rest after collision. And since the car that hit the water barrels was brought to rest at a longer time, it has a greater change in momentum
Prove that you can do a one foot spin.
A force of 20 N to the south is applied to each object below. Which object will undergo the greatest change in momentum?
Answer:
Hello there! The answer your would be looking for is:
A 33 kg object that is moving north at 10 m/s
Momentum can be defined as the product of mass and velocity. Thus momentum is directly proportional to both velocity and momentum. Thus, the object with greater mass as well as velocity has greater momentum. Therefore, option C is correct.
What is force?Force can be described as an external agent acting on a body, to change its state of rest or motion. There are several kinds of forces such as magnetic force, frictional force, nuclear force, etc.
In physics, force can be described as the product of the mass and acceleration of the body. Greater mass results in greater force required to be exerted on the object to make it move or stop.
Therefore, when mass or velocity or both increases, the momentum of the object increases as well. Therefore, the larger object moving faster gain greater momentum.
Therefore, when the same force is exerted on the object then, the 41 kg object that is moving north at 12 m/s will undergo the greatest change in momentum.
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Your question was incomplete but most probably the complete question was,
A force of 20 N to the south is applied to each object below. Which object will undergo the greatest change in momentum?
A. A 33 kg object that is moving north at 12 m/s
B. A 41 kg object that is moving north at 10 m/s
C. A 41 kg object that is moving north at 12 m/s
D. A 33 kg object that is moving north at 10 m/s
An engineer is designing the runway for an airport. Of the planes that will use the airport, the lowest acceleration rate is likely to be 3 m/s2. The takeoff speed for this plane will be 65 m/s. All airplanes will start from rest(0m/s). Assuming this minimum acceleration, what is the minimum allowed length for the runway for take off?
Answer:
x = 704 [m]
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f} ^{2} =v_{o} ^{2} +2*a*x[/tex]
where:
Vf = final velocity = 65 [m/s]
Vo = initial velocity = 0 (starts from rest)
a = acceleration = 3 [m/s²]
x = distance [m]
Now replacing we have:
65² = 0 + 2*3*x
4225 = 6*x
x = 704 [m]
What happens when the elevator is in free-fall, that is, what is the value for FN and what is the sensation experienced by the person in the elevator? Also, discuss the meaning of FN<0.
Answer:
Weightlessness
Explanation:
When the elevator is in free fall, this can only occur when the cord of the elevator breaks.
The acceleration of the elevator will be equal to the acceleration due to gravity. That is:
a = g
Then, the body will experience what we called WEIGHTLESSNESS
Where the normal reaction N of the person will tend to zero. That is
N = 0
The value of FN < 0 because the person inside the lift will experience weightlessness.
What produces the Coriolis Force on the movement of Earth's air masses? The rotation of the Earth from east to west. Warm light air from the Equator moves north. The rotation of the Earth from west to east. Heavy cool air from the north moves south.
Answer:
The rotation of the Earth from west to east.
Explanation:
The rotation of the Earth from west to east causes the winds near to equator to move towards the west and the winds in the northern and southern regions of the Earth to move east.
The instance that produces the Coriolis Force on the movement of Earth's air masses is the rotation of the Earth from west to east. Thus, the correct option for this question is C.
What is Coriolis force?Coriolis force may be defined as a type of apparent force that as a result of the rotation of the earth effectively deflects the migrating objects to the right in the northern hemisphere and to the left in the southern hemisphere.
The process of rotating Earth from west to east remarkably stimulates the winds near the region of the equator in order to move towards the west and the winds in the northern and southern regions of the Earth to incidentally move to the east. The Coriolis force applies to movement on rotating objects. It is determined by the mass of the object and the object's rate of rotation.
Therefore, the correct option for this question is C.
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A satellite was in two separate crashes. In both crashes, the satellite had the same mass. Engineers want to know about the speed and direction of the satellite after the crashes. Why would the crash affect the motion of the satellite, and which crash caused a greater change in motion for the satellite?
WILL GIVE BRAINLIEST
Answer:
The fastest satellite must change orbit
The most massive body (m₁) transfers more momentum to the satellite,
Explanation:
For this problem we consider a system formed by the satellite and each of the bodies with which it collides, in this system the forces during the collision are internal, the amount of movement must be conserved. Let's write the momentum is two instants
Most massive body (m1)
initial. Before the crash
p₀₁ = M v + m₁ v₁
after the crash
[tex]p_{f1}[/tex] = M v´ + m₁ v₁´
how momentum is conserved
p₀ = p_{f}
Lighter body (m2)
p₀₂ = M v + m₂ v₂
p_{f2} = M v´ + m₂ v₂´
Let's clarify that the speed of the satellite and the object do not have the same direction, in general these shocks are elastic.
We can see that p₀₁> p₀₂
Let us analyze the two cases when the body collides, The most massive body (m₁) transfers more momentum to the satellite, therefore there must be a greater change in its momentum and velocity.
The fastest satellite must change orbit, thus rotating at a different distance from Earth
Air enters into the hollow propeller tube at A with a mass flow of 4 kg/s and exits at the ends B and C with a velocity of 400 m/s, measured relative to the tube. If the tube rotates at 1500 rev/min, determine the frictional torque M on the tube.
Answer:
643N.m
Explanation:
From this question we have:
Mass flow = 4kg/s
Velocity V = 400m/s
Rotation N = 1500rev/min
We get the relative velocity at exit to be:
V2 = V - r2w
400-0.5x [(2*π*1500)/60]
= 400-78.5
= 321.5m/s
Then we have to calculate the frictional torque My
Mt = Mr2 x V2
= 4x0.5x321.5
= 643Nm
From the calculations above, we get the frictional torque M on the tube to be 643Nm.
During a baseball game, a batter hits a popup to a fielder 83 m away.
The acceleration of gravity is 9.8 m/s
2
.
If the ball remains in the air for 5.7 s, how
high does it rise?
Answer in units of m
Answer:
The height risen by the ball is 39.8 m.
Explanation:
Given;
total time spent in air by the ball, t = 5.7 s
time to rise to maximum height, t = 5.7 /2 = 2.85 s
The initial velocity of the ball is given by;
v = u - gt
where;
v is the final velocity at maximum height = 0
u is the initial velocity of the ball
0 = u - gt
u = gt
u = (9.8 x 2.85)
u = 27.93 m/s
The vertical height traveled by the ball is given by;
v² = u² - 2gh
where;
v is the final velocity of the ball at maximum height = 0
g is acceleration due to gravity = 9.8 m/s²
0 = u² - 2gh
2gh = u²
h = u² / 2g
h = (27.93)² / ( 2 x 9.8)
h = 39.8 m
Therefore, the height risen by the ball is 39.8 m.
A 5kg rock is lifted 2m. Find the amount of work done.
Answer:
98J
Explanation:
Given parameters:
Mass of rock = 5kg
Height = 2m
Unknown:
Work done = ?
Solution:
The amount of work done is given as:
Work done = Force x distance
Work done = Weight x height
Work done = mgH
Now insert the parameters and solve;
Work done = 5 x 9.8 x 2 = 98J
The amount of work done on the rock is equal to 98 Nm.
Given the following data:
Mass of rock = 5 kgDistance = 2 metersTo determine the amount of work done:
First of all, we would calculate the force acting on the rock:
[tex]Force = mg\\\\Force = 5 \times 9.8[/tex]
Force = 49 Newton
Now, we can determine the amount of work done:
[tex]Work \;done = force \times distance\\\\Work \;done = 49 \times 2[/tex]
Work done = 98 Nm
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