1) A rock of mass 1.50kg is released from rest at a height of 30m. Ignore air resistance and
calculate;
(a) its speed half way down
(b) its speed on reaching the ground
(c) its total mechanical energy
(i) at a height of 30m
(ii) its kinetic energy half way through
(iii) its potential energy on striking the ground

Answer:

Explanation:

Given the following data;

Mass = 9.1 X 10^{-31} kg

Velocity = 4.8x10⁵ m/s

Planck’s constant ( h ) = 6.6262 * 10^{-34}

To find the wavelength;

Applying de broglie's equation;

Wavelength = h/mv

Wavelength = ) = 6.6262 * 10^{-34}/(9.1 X 10^{-31} * 4.8x10⁵)

Wavelength = 1.52 * 10^{-71} meters

The release of infrared light from radioactive materials is what demonstrates light possessing wave characteristics.

This is defined as the propagation of disturbances from one place to another in an organized way.

The release of waves in a diffraction pattern is why option C was chosen as the most appropriate choice.

Read more about Wave here https://brainly.com/question/15663649

Answer:

Explanation:

v = ir

v/r = i

112/43 = i

2.60 ≈ i

Answer:

c.an electron or positron

Answer:

your answer would be c

Explanation:

Answer:

One degree unit on the Celcius scale is equivalent to one degree unit on the kelvin scale. The only difference between these two scales is the zero point. The zero point on the Celcius scale was defined as the freezing point of water, which means that there are higher and lower temperatures around it.

Hi there!

[tex]\large\boxed{PE = 7.35 J, \text{ }v \approx 3.13 m/s}[/tex]

To find the potential energy of the ball at B, we can use the equation:

PE = mgh

Plug the given gravity, mass, and height:

PE = (1.5)(0.5)(9.8) = 7.35 J

At A, all of this potential energy is changed to kinetic energy, so we can use the following equation:

v = √2KE/m

Plug in the solved for energy and mass:

v = √2(7.35)/1.5

Solve:

v ≈ 3.13 m/s

Answer:

The ability to adapt is important because :

1) It helps in the survival of human beings.

2) It brings more variation to the human kind.

3) It helps the species from getting endangered or extinct.

4) It brings transformation in the adapting kind.

Hope this helps you☺️☺️

Answer:

The wavelength of a wave with the frequency of 330hz and a speed of 343m/s would be 1.04m

Explanation:

You can get the wavelength of a wave by dividing the speed of the wave by its frequency, which in this case would be:

343/300, which as a decimal number, it'd be 1.04.

I hope I helped you, and a "Brainliest" is always appreciated! ☺

Answer:

800J

Explanation:

Using the formula for change in the internal energy of a system

∆U = Q - W

Q = heat added to the system

W =workdone by system.

We know the process is an adiabatic one then, there no addition/ removal of heat, then Q= 0

(∆U = -W )

Then substitute for W, we have

∆U = -[-800]

∆U= 800J

∆U = 800J

Answer:

melting butter in a saucepan, as the butter cools it turns brown

Explanation:

although melting the butter is a physical change, but the butter being cooked and turning brown Is a chemical change, because due to the heat, its particles are being broken down, which is irreversible, and shows a chemical change.

Explanation:

V= Current × Resistance

V= 400mA × 5kohms

V= 2000V

Explanation:

lol ....you are right.......

Answer:

the current INCREASES.

Explanation:

In this experiment, the electrons are generated by a filament with very low speed, when they are subjected to a difference and potential ΔV they acquire the necessary speed to reach the regulation and the current can be measured.

Some electrons collide elastically with the atoms of the mercury gas that is much heavier and are scattered in any direction, so they do not reach the grid, by increasing the voltage this scattered electrons can acquire the necessary speed in the direction of grid to reach it and therefore are also measured, increasing the current.

Therefore, as the power difference increases, the current INCREASES.

Complete question is;

Shoveling snow can be extremely taxing since the arms have such a low efficiency in this activity. Suppose a person shoveling a sidewalk metabolizes food at the rate of 800 W. (The efficiency of a person shoveling is 3%.)

(a) What is her useful power output? (b) How long will it take her to lift 3000 kg of snow 1.20 m? (This could be the amount of heavy snow on 20 m of footpath.) (c) How much waste heat transfer in kilojoules will she generate in the process?

Answer:

A) P_out = 24 W

B) t = 1470 s

C) Q = 1140.72 KJ

Explanation:

We are given;

Input Power; P_in = 800 W

Efficiency; η = 3% = 0.03

A) Formula for efficiency is;

η = P_out/P_in

Making P_out the subject, we have;

P_out = η•P_in

P_out = 0.03 × 800

P_out = 24 W

B) We know that;

Power = work done/time taken

Thus;

P_out = mgh/t

We are given;

m = 3000 kg

h = 1.20 m

Thus, time is;

t = (3000 × 9.8 × 1.2)/24

t = 1470 s

C) amount of heat wasted is calculated from;

Q = (P_in - P_out)t

Q = (800 - 24) × 1470

Q = 1,140,720 J

Q = 1140.72 KJ

Answer: I believe hydrogen cyanide, carbon monoxide, and ammonia are the three chemicals involved, but im not sure

Answer:

0.06

Explanation:

Working on the problem at hand i calculated and got my answer to around simplified at 0.06

Answer moderate alcohol can be good for you health

Explanation: but I wouldn't do none of those things to be honest

SMARTEST

Answer:

none of the above

Explanation:

its an easy question haha

Answer:

True

Explanation:

Answer:

a) [tex](v_1)=0.3989m/s[/tex]

b) [tex]\theta_1=80.5 \textdegree[/tex]

c) [tex]K.E=0.036J[/tex]

Explanation:

From the question we are told that:

Initial speed of 1st ball [tex]u_{1}=0 m/s[/tex]

Mass of 1st ball [tex]m_1=0.585kg[/tex]

Mass of 2nd ball [tex]m_2=0.420kg[/tex]

Initial speed of 2nd ball [tex]u_{2}=0.270 m/s[/tex]

Final speed of 2nd ball [tex]v_{2}=0.220 m/s[/tex]

Angle of collision [tex]\angle=36.9 \textdegree[/tex]

a)

Generally the equation for law of conservation is mathematically given by

[tex]m_1u_1+m_2u_2=m_1v_1^2+m_2v_2^2[/tex]

The final velocity [tex]v_1[/tex] is given as

[tex]0+(0.420)(0.270)=(0.585)(v_1)^2+(0.420)(0.220)^2[/tex]

[tex](v_1)^2=\frac{(0.420)(0.270)-(0.420)(0.220)^2}{0.585}[/tex]

[tex](v_1)^2=0.1591[/tex]

[tex](v_1)=0.3989m/s[/tex]

b)

Generally the equation for law of conservation is mathematically given by

[tex]m_1u_1+m_2u_2=m_1v_1cos\theta_1+m_2\theta_2[/tex]

[tex]0+(0.420)(0.270)=(0.585)(1.511)cos\theta_1+(0.420)(0.220)cos36 \textdegree[/tex]

[tex]cos\theta_1= \frac{(0.420)(0.270)-(0.420)(0.220)cos36 \textdegree}{(0.585)(0.3989)}[/tex]

[tex]cos\theta_1=0.1656[/tex]

[tex]\theta_1=80.5 \textdegree[/tex]

c)

Generally the equation for kinetic energy is mathematically given by

[tex]K.E=\frac{1}{2} mv^2[/tex]

1st Ball

[tex]K.E=\frac{1}{2} (0.585)(0.3989)^2[/tex]

[tex]K.E=0.0465J[/tex]

2nd ball

[tex]K.E=\frac{1}{2} (0.420)(0.220)^2[/tex]

[tex]K.E=0.101J[/tex]

Therefore the  change in the total kinetic energy of the two balls as a result of the collision is

[tex]0.101-0.0465[/tex]

[tex]K.E=0.036J[/tex]

Answer: True!

Explanation: The force is proportional to the square of the distance between 2 point masses

Answer:

a. E = 900000 J = 900 KJ

b. ΔT = 8.18 °C

c. Cost = $ 7.2  

Explanation:

a.

The energy can be given by:

[tex]E = Pt[/tex]

where,

E = Energy = ?

P = Power = 500 W

t = time = (0.5 h)(3600 s/1 h) = 1800 s

Therefore,

[tex]E = (500\ W)(1800\ s)[/tex]

E = 900000 J = 900 KJ

b.

The change in temperature of room air is given by the following formula:

[tex]0.5E = mC\Delta T\\[/tex]   (since 50% of energy is used to heat air)

where,

m = mass of air = 50 kg

C = specific heat of air = 1.1 KJ/kg.°C

ΔT = Change in temperature of air = ?

Therefore,

[tex](0.5)(900\ KJ) = (50\ kg)(1.1\ KJ/Kg.^oC)\Delta T[/tex]

ΔT = 8.18 °C

c.

First, we will calculate the total energy consumed:

[tex]E = (0.5\ KW)(6\ h/d)(30\ d)\\E = 90\ KWh[/tex]

Now, for the cost:

[tex]Cost = (Unit\ Cost)(Energy)\\Cost = (\$ 0.08\KWh)(90\ KWh)[/tex]

Cost = $ 7.2

Answer:

Im just here for the points man sorry

Explanation:

Answer:

Approximately [tex]281.25\; \rm m[/tex]. (Assuming that the drag on this ball is negligible, and that [tex]g = 10\; \rm m \cdot s^{-2}[/tex].)

Explanation:

Assume that the drag (air friction) on this ball is negligible. Motion of this ball during the descent:

The horizontal velocity of this ball is constant during the descent. The horizontal distance that the ball has travelled during the descent is also given: [tex]x(\text{horizontal}) = 30\; \rm m[/tex]. Combine these two quantities to find the duration of this descent:

[tex]\begin{aligned}t &= \frac{x(\text{horizontal})}{v(\text{horizontal})} \\ &= \frac{30\; \rm m}{4\; \rm m \cdot s^{-1}} = 7.5\; \rm s\end{aligned}[/tex].

In other words, the ball in this question start at a vertical velocity of [tex]u = 0\; \rm m \cdot s^{-1}[/tex], accelerated downwards at [tex]g = 10\; \rm m \cdot s^{-2}[/tex], and reached the ground after [tex]t = 7.5\; \rm s[/tex].

Apply the SUVAT equation [tex]\displaystyle x(\text{vertical}) = -\frac{1}{2}\, g \cdot t^{2} + v_0\cdot t[/tex] to find the vertical displacement of this ball.

[tex]\begin{aligned}& x(\text{vertical}) \\[0.5em] &= -\frac{1}{2}\, g \cdot t^{2} + v_0\cdot t\\[0.5em] &= - \frac{1}{2} \times 10\; \rm m \cdot s^{-2} \times (7.5\; \rm s)^{2} \\ & \quad \quad + 0\; \rm m \cdot s^{-1} \times 7.5\; s \\[0.5em] &= -281.25\; \rm m\end{aligned}[/tex].

In other words, the ball is [tex]281.25\; \rm m[/tex] below where it was before the descent (hence the negative sign in front of the number.) The height of this cliff would be [tex]281.25\; \rm m\![/tex].

Frequency, is defined as the rate of rotation, or the number of rotations in some unit of time. Angular frequency, , is the rotation rate measured in radians. These three quantities are related by f = 1 T = ω 2 π .

The frequency is the number of oscillation per unit time and it is used for defining the cyclic process like rotation, oscillation, wave etc.

The SI unit of the frequency is denoted as Hertz and the symbol λ represents it where one hertz means the wave completed one cycle in one second.

The frequency which explains the phenomenon of oscillatory and vibration like the mechanical vibration, sound signals, light, frequency waves etc. The  “period” represented as the time required by the wave for one oscillation, i.e., it is inversely proportional to the frequency.

If the flashes, then the period is the time between the two flashes. And the frequency is the total number of flashes per second.

For more details regarding frequency, visit

brainly.com/question/14400059

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Answer:

Either heat added or mechanical work done.

Explanation:

Since he found stirring rod on the desk and a cigarette lighter. This means that the beaker was probably either heated with the aid of fire from the lighter.

Also, the stirring rod could have been used to stir the water which will increase the kinetic energy which also means an increase in temperature.

Thus, it's either heat was added or mechanical work was done as a result of stirring.

Answer:

[tex]T_d=2.8*10^-^6\%[/tex]

Explanation:

From the question we are told that

Distance b/w Earth and the moon [tex]d_e=3.84×10^8 m[/tex]

Thickness of Earth's atmosphere[tex]d_t=30km[/tex]

Constant index of refraction [tex]n = 1.000293.[/tex]

Generally the equation for percentage of time delay [tex]T_d[/tex] is mathematically given as

[tex]T_d=\frac{d(n-1)}{rm}*100\%[/tex]

[tex]T_d=\frac{(35*10^3)(1.000293-1)()100)}{3.674*10^8} *\%[/tex]

[tex]T_d=2.8*10^-^6 \%[/tex]

Therefore the general percentage correction needed because of tym deley is given as

[tex]T_d=2.8*10^-^6\%[/tex]

Solution :

We know that the time period of oscillation of a spring mass system is given by :

[tex]$T = 2 \pi \sqrt{\frac{m}{k}}$[/tex]     , where m is mass and k is the spring constant

∴ [tex]$T_A = 2 \pi \sqrt{\frac{m}{k}}$[/tex]    .........(i)

  [tex]$T_B = 2 \pi \sqrt{\frac{2m}{k}}$[/tex] ..........(ii)

  [tex]$T_C = 2 \pi \sqrt{\frac{3m}{6k}} = 2 \pi \sqrt{\frac{m}{2k}}$[/tex]   ..........(iii)

  [tex]$T_D = 2 \pi \sqrt{\frac{m}{4k}}$[/tex]   ...............(iv)

Comparing the equations (i), (ii), (iii) and (iv)

We get

[tex]$T_B > T_A > T_C > T_D$[/tex]

So in increasing order of time period, we get

[tex]$T_D < T_C < T_A < T_B$[/tex]

Answer:

Speed of bike = 2.5 km/h

Distance travel = 1,000 km (Approx.)

Explanation:

Given:

Distance cover by Helmut = 5 km

Time taken = 2 hour

Find:

Speed of bike

Computation:

Speed = Distance / Time

Speed of bike = 5 / 2

Speed of bike = 2.5 km/h

Given:

Speed of plane = 250 km/h

time taken = 3 hr 58 min = 3.967 hr

Find:

Distance travel

Computation:

Distance = Speed x time

Distance travel = 250 x 3.967

Distance travel = 991.669

Distance travel = 1,000 km (Approx.)