Answer:
60008.4 J
Explanation:
The mass of each kid = 30 kg
mass of the cart = 20 kg
The speed of the cart down the hill = 30 km/hr = 30 x 1000/3600 = 8.33 m/s
The height of the hill = 80 m
The potential energy of the boys at the top of the hill = mgh
where
m is the total mass of the kids and the cart = (30 x 2) + 20 = 80 kg
g is the acceleration due to gravity = 9.81 m/s^2
h is their height above the ground = 80 m (on the top of the hill)
substituting, we have
potential energy PE = 80 x 9.81 x 80 = 62784 J
At an instance at the bottom of the hill
their kinetic energy = [tex]\frac{1}{2} mv^2[/tex]
where
v is their velocity = 8.33 m/s
m is their total mass = 80 kg
substituting, we have
kinetic energy KE = [tex]\frac{1}{2}*80*8.33^2[/tex] = 2775.6 J
Total work done on the cart is equal to the energy lost by the cart when it reached the bottom of the hill
work done by friction = PE - KE = 62784 - 2775.6 = 60008.4 J
If the toy helicopter weighs 115N and its hovering motionless in the air. What is the force that the helicopters propeller must exert?
Physics, really easy
Answer:
I am pretty sure its C
Explanation:
An object increases its speed from rest to 35 m/s while traveling over a distance of
400 meters. Determine the acceleration of the object.
Answer:
1.53 m/s²
Explanation:
Given:
Δx = 400 m
v₀ = 0 m/s
v = 35 m/s
Find: a
v² = v₀² + 2aΔx
(35 m/s)² = (0 m/s)² + 2a (400 m)
a = 1.53 m/s²
What is Average rainfall in the desert?
Answer:
less than 10 inches, or 25 centimeters, of precipitation a year.
Explanation:
PS. the precipitation recieved in the desert can be in the form of either rain or snow.
what is the nature of image of Sun obtained on a paper with the help of concave mirror
Answer:
Because concave mirror focus the sunlight at one particular point . At that particular point , amount of sunlight is converged and heat is trapped at that point . This is because , it burn the paper on which the image is focussed .
Which of the following is the energy stored in an object as a result of its vertical position or height? Elastic potential energy Gravitational potential energy Kinetic energy Thermal energy
Answer:
Gravitational potential energy
Explanation:
Gravity would act upon it if it were not suspended.
Answer: Gravitational potential energy
Explanation: I did the quiz! Hope it helped!
A moon rock is dropped from a cliff and it takes 2 seconds for the rock to fall 6.6 meters. What is the moon rock’s average speed?
Average speed = (total distance) / (time to cover the distance)
Speed = (6.6 meters) / (2 seconds)
Speed = 3.3 m/s
so i need help with waves what is a transverse wave
Answer:
A wave in which the medium vibrates at right angles to the direction of the propagation is called transverse wave.
identify me iam a nutrient in food does not require chemical other than a paper to food.
Answer:
Fats can be identified with a paper without any chemical. Just the food sample in Fats should be placed on the first paper than the rest three papers should be placed on and if any marks are there that shows the quantity of presence in Fats.
Explanation:
Plz Mark me as brainliest
ball is dropped from the height H the total distance covered in last second of its motion is equal to distance covered in first 3 second. find the height.
pls answer this question correctly and don't give any irrelevant or else I will report the answer....
[tex]\rm{\gray{\underline{\underline{\blue{GIVEN:-}}}}}[/tex]
A ball is dropped from a height = HThe total distance covered in last second of its motion is equal to the distance covered in first 3 second .[tex]\rm{\gray{\underline{\underline{\blue{TO\:FIND:-}}}}}[/tex]
The height of the journey .[tex]\rm{\gray{\underline{\underline{\blue{SOLUTION:-}}}}}[/tex]
We have know that,
[tex]\green\bigstar\:\rm{\gray{\overbrace{\underbrace{\red{S\:=\:ut\:+\:\dfrac{1}{2}\:at^2\:}}}}}[/tex]
Where,
S = Distance .u = initial velocity = 0m/st = time = 3sa = acceleration[Note :- Here, acceleration is ‛acceleration due to gravity’ .]
a = 10m/s^2=> S = 1/2 × 10 × (3)^2
=> S = 5 × 9
=> S = 45m -----(1)
✒ If the ball takes ‛n’ second to fall the ground, then distance covered in nth second is,
[tex]\green\bigstar\:\rm{\gray{\overbrace{\underbrace{\red{S_n\:=\:u\:+\:\dfrac{g}{2}\:(2n\:-\:1)\:}}}}}[/tex]
=> Sn = 0 + 10/2 (2 × n - 1)
=> Sn = 5 (2n - 1)
=> Sn = 10n - 5 -----(2)
Therefore,
10n - 5 = 45=> 10n = 45 + 5
=> n = 50/10
=> n = 5
Now put the value of ‛n = 5’ in equation(2), we get
=> Sn = 10 × 5 - 5
=> Sn = 50 - 5
=> Sn = 45m
[tex]\rm{\pink{\therefore}}[/tex] The height of the journey is “ 45m ” .
Please help me with thus question (picture) D:
well thanks for the Information
Explanation:
Torque = Force * Perpendicular distance of the force = 10N * 0.8m = 8Nm.
In diagram A, both torques are acting in a clockwise direction. Hence the net torque is 2N * 1m + 4N * 1m = 6Nm, clockwise.
In diagram B, the torques are acting in opposite directions. For the clockwise one, its torque is 5N * 4m = 20Nm. For the anticlockwise one, its torque is 2N * 10m = 20Nm. Since they are in opposite directions and are equal, they cancel out each other.
Hence net force = 0N and net torque = 0Nm.
What do you dislike about science?
Answer:
nngh have
bjruh hjrhhj be rnrnnrnrnnnrnjrjnnnnnnnnrnrn n n and I was nrn
Explanation:
jbbbbbhhhjjnnnnnnnnnnjhvcc
Explanation:
A ball is dropped from the roof of the A200 building. How fast is a traveling 0.5 seconds later?
ANYTHING that's dropped near the Earth's surface and isn't affected by air resistance falls 9.8 m/s faster at any time than it did 1 second earlier.
0.5 second after it was dropped with zero speed, it's falling at
(0.5) x (9.8 m/s) = 4.9 m/s .
It makes no difference which building it was dropped from.
what is kinetic energy
Answer:
Kinetic energy is the energy possessed in a body in motion
Answer:
wind energy is also called kinetic energy
A cliff jumper jumps off a cliff with an initial horizontal velocity of 10 m/s. The cliff is 10 meters high. How far from the base of the cliff does the diamond fall?
Answer:
The distance reached is 14.3 m.
Explanation:
To find the distance reached by the diamond first we need to find the flight time:
[tex] t_{v} = \sqrt{\frac{2h}{g}} [/tex]
Where:
h: is the height = 10m
g: si the gravity = 9.81 m/s²
[tex] t_{v} = \sqrt{\frac{2h}{g}} = \sqrt{\frac{2*10 m}{9.81 m/s^{2}}} = 1.43 s [/tex]
Now, we can find the distance reached:
[tex] x = V_{0_{x}}*t_{v} [/tex]
Where:
[tex]V_{0_{x}}[/tex] is the initial horizontal velocity = 10 m/s
[tex] x = V_{0_{x}}*t_{v} = 10 m/s*1.43 s = 14.3 m [/tex]
Therefore, the distance reached is 14.3 m.
I hope it helps you!
Miles and Allison are conducting a science experiment on bacteria and
they have a different hypothesis about what is going to happen. After
repeating their experiment several times, they realize that the results of
the experiment do not clearly support either hypothesis. What should
Miles and Allison do next?
O A. assume Miles hypothesis is correct
O B. revise their hypotheses and do another test
C. change their results to match one of their hypotheses
O D. repeat the experiment until it supports one of their hypotheses
What is the main function of chloroplasts?
Choose 1 answer:
(Choice A)
A
To store food, water, and waste
(Choice B)
B
To package and sort proteins
(Choice C)
C
To convert sunlight into usable sugars
(Choice D)
D
To produce ATP for the cell
Answer:
C
To convert sunlight into usable sugars
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Explanation:
what is weight ?on what factor does it depend.
Answer:
weight is the mass of an object
it is depends on mass of the body.
Answer:
the force with which an object near the earth on another celestial body is atteracted toward the center of the body by gravity. an objects weight depends on its mass
What are the characteristics of high energy waves?
Answer:
High energy waves are louderHave a higher amplitudePeaks are higher and the valleys are lowerExplanation:
*Hope this helps*
Identify the subatomic particle that is NOT contained in the nucleus. A) electron B) neutron C) nucleus D) proton
Answer:
The answer is A.
Explanation:
Electrons are found outside of a nucleus.
You drive for 5 hours at a speed of 70 km/hr. How far did you go?
Answer:
350 miles
Explanation:
because multiply 70 times 5 and you will get 350
Which statement describes the energy involved in diffusion?
O Diffusion requires energy in all cases.
O Diffusion requires energy only to move material in through the cell membrane.
O Diffusion does not require energy in any situation.
O Diffusion requires energy only to move material out through the cell membrane.
Answer:
So B
Explanation:
The statement that the energy involved in diffusion is as follows:
Diffusion does not require energy in any situation.Thus, the correct option is C.
What is Diffusion?Diffusion may be defined as the process of migration of substances or molecules through a semipermeable membrane from an area of higher concentration to an area of lower concentration.
Diffusion does not require energy because it is classified under the passive transport of materials. Diffusion always works towards the concentration gradient.
Energy is typically involved when the movement occurs against the concentration gradient like active transport.
Therefore, the correct option for this question is C.
To learn more about Diffusion, refer to the link;
https://brainly.com/question/94094
#SPJ6
define aperture of a spherical mirror
The diameter of the reflecting surface of spherical mirror is called its aperture. Mirrors whose aperture is much smaller than its radius of curvature, we use R=2f.
What are two causes of friction? *
Answer: Friction is a force that resists the relative motion between two objects or materials. The causes of this resistive force are molecular adhesion, surface roughness, and deformations. Adhesion is the molecular force resulting when two materials are brought into close contact with each other
A light-rail train going from one station to the next on a straight section of track accelerates from rest at 1.1 m/s^2 for 20s. It then proceeds at constant speed for 1100m before slowing down at 2.2m/s^2 until it stops at the station. A) What is the distance between stations? B) How much time does it take the train to go between the stations?
Answer:
A) The distance between the stations is 1430m
B) The time it takes the train to go between the stations is 80s
Explanation:
First we will calculate the distance covered for the first 20s.
From one the equations of kinematics for linear motion
[tex]S = ut + \frac{1}{2}at^{2} \\[/tex]
Where [tex]S[/tex] is distance traveled
[tex]u[/tex] is the initial velocity
[tex]t[/tex] is time
and [tex]a[/tex] is acceleration
Since the train starts from rest, [tex]u[/tex] = 0 m/s
Hence, for the first 20s
[tex]a =[/tex] 1.1 m/s²; [tex]t =[/tex] 20s, [tex]u[/tex] = 0 m/s
∴ [tex]S = ut + \frac{1}{2}at^{2} \\[/tex] gives
[tex]S = (0)(20) + \frac{1}{2}(1.1)(20)^{2}[/tex]
[tex]S = \frac{1}{2}(1.1)(20)^{2}[/tex]
[tex]S =[/tex] 220m
This is the distance covered in the first 20s.
The train then proceeds at constant speed for 1100m.Now, we will calculate the speed attained here
From
[tex]v = u +at[/tex]
Where [tex]v[/tex] is the final velocity
Hence,
[tex]v = 0 + 1.1(20)[/tex]
[tex]v = 1.1(20)[/tex]
[tex]v =[/tex] 22 m/s
This is the constant speed attained when it proceeds for 1100m
The train then slows down at a rate of 2.2 m/s² until it stopsWe can calculate the distance covered while slowing down from
[tex]v^{2} = u^{2} + 2as[/tex]
The initial velocity, [tex]u[/tex] here will be the final velocity before it started slowing down
∴[tex]u[/tex] = 22 m/s
The final velocity will be 0, since it came to a stop.
∴ [tex]v[/tex] = 0 m/s
[tex]a = -[/tex]2.2 m/s² ( - indicates deceleration)
Hence,
[tex]v^{2} = u^{2} + 2as[/tex] gives
[tex]0^{2} =22^{2} +2(-2.2)s[/tex]
[tex]0=22^{2} - (4.4)s\\4.4s = 484\\s = \frac{484}{4.4} \\s = 110m[/tex]
This is the distance traveled while slowing down.
A) The distance between the stations is
220m + 1100m + 110m
= 1430m
Hence, the distance between the stations is 1430m
B) The time it takes the train to go between the stations
The time spent while accelerating at 1.1 m/s² is 20s
We will calculate the time spent when it proceeds at a constant speed of 22 m/s for 1100m,
From,
[tex]Speed =\frac{Distance}{Time}\\[/tex]
Then,
[tex]Time = \frac{Distance}{Speed}[/tex]
[tex]Time = \frac{1100}{22}[/tex]
Time = 50 s
And then, the time spent while decelerating (that is, while slowing down)
From,
[tex]v = u + at\\0 = 22 +(-2.2)t\\2.2t = 22\\t = \frac{22}{2.2} \\t= 10 s[/tex]
This is the time spent while slowing down until it stops at the station.
Hence, The time it takes the train to go between the stations is
20s + 50s + 10s = 80s
The time it takes the train to go between the stations is 80s
How is it possible to charge electrical devices when the power is out?
Need help in class right now
Answer:
2.05pm.
Explanation:
In the picture.
1. How do energy and matter recycle in a closed-loop system?
Answer:
In a closed-loop system, matter is used to generate energy, and the energy generated is used to produce matter, and the cycle goes on without end.
Explanation:
A closed-loop system is one in which materials or energy is recycled without end through a production cycle. This means that a raw material is used to produce a finished product, and the finished product at the end of its use cycle is converted back and used as a raw material to produce more of it again. Energy and matter can also be cycled in the same way in an energy and matter closed-loop system, converting matter to energy, and the energy is put back into the production of more of the matter.
In a closed system loop, the matter has been recycled to provide raw material and form new products. The energy formed by the product has been recycled by being used by the raw materials for the formation of new products.
The closed system loop can be defined as the system in which the products and energy has been recycled continuously to form more products. The energy has been formed in the closed system loop, that can be utilized by the raw materials for the production of energy.
The products formed after reaching the equilibrium of the formation, and dissociation reaches the point, and starts to dissociate to provide the raw material to the system.
Thus, in a closed system loop, the matter has been recycled to provide raw material and form new products. The energy formed by the product has been recycled by being used by the raw materials for the formation of new products.
For more information about a closed system loop, refer to the link:
https://brainly.com/question/11995211
a man pulls a box with a force of 90.0 N directed along the handle which makes angle of 45 degrees with the ground. find the horizontal and vertical components of this force
Answer:
The horizontal component of the force, Fₓ = 63.64 N
The vertical component of the force, [tex]F_y[/tex] = 63.64 N
Explanation:
Given;
magnitude of the force, F = 90 N
angle between the handle and the ground, θ = 45°
The horizontal component of the force, Fₓ = Fcosθ
Fₓ = 90 x cos45
Fₓ = 63.64 N
The vertical component of the force, [tex]F_y = Fsin \theta[/tex]
[tex]F_y[/tex] = 90 sin45
[tex]F_y[/tex] = 63.64 N
Therefore, the horizontal and vertical components of the force is 63.64 N.
how much time will it take for the sound of thunder to travel 1,550 meters if sound travels at a speed of 340 m/s
Answer:
4.55 seconds
Explanation:
Speed=distance / Time
So Time = Distance /speed
=1550/340