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Using standard formulae, derive an expression for the final speed of a falling object in terms of its change in height. Assume zero air resistance or other resistive forces.

E k = (1/2)mv 2 E p = mg(dh) Set these equal to each other, because of conservation of energy: (1/2)mv 2 = mg(dh) Cancel the mass: (1/2)v 2 = g(dh) v 2 = 2g(dh) v = (2g(dh)) 1/2
DL
Answered by Danny L. • Physics tutor
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Explain how a convection current forms when a pan of water is being heated over a stove

The covection current forms because the base of the pan heats up as it gains energy from the stove via conduction, the pan then subsequently heats the water that is close to the bottom. As the water gains he...
JH
Answered by Jack H. • Physics tutor
18300 Views

Why, in a thermal flask, does having a vacuum layer help keep the coffee warm?

Heat is transferred by 3 processes, conducation, convection and radiation. Having a vacuum layer stops heat being transferred away from the coffee by conduction. Conduction works by air molecules bumping int...
BO
Answered by Benjamin O. • Physics tutor
3639 Views

What is the wavelength of a wave?

First I would draw a graph showing a wave to support my explanation for what the wavelength means. The wavelength of a wave is the distance, in metres, from one point of the wave to the same point on the nex...
KW
Answered by Kimberley W. • Physics tutor
3252 Views

Calculate the acceleration if a force of 500N is exerted on a mass of 20kg

Using F=Ma, rearrage for a, a= 500/20, the acceleration is 25m/s 2
PL
Answered by Patrick L. • Physics tutor
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