Search our library of Physics questions

Top answers

Physics

All levels

A runner of weight 588N runs at a speed of 8 miles/hr. What is the kinetic energy of the runner? Determine the power exerted by the runner over a distance of 10m.

KE = 1/2mv^2m = 588/9.8 = 60 kgv = 8 miles/hr = 3.56 m/sKE = 379 JP = E/tt = d/v = 10m/3.56m/s = 2.81 sP = 135 W

2728 Views

In the Rutherford alpha scattering experiment, most particles passed straight through the foil with little or no deflection. What can be deduced about the structure of the atom from this?

Answer: Most of the atom's mass must be concentrated in a small area at the centre of the atom. This is known as the nucleus.

Answered by Megan R. • Physics tutor

2501 Views

Explain the difference between energy and power.

Power is the rate at which energy is transferred. For example, a typical kettle may use 1.2 kiloWatts (kW) for about 2 minutes to boil water. This means that the kettle uses 1200 Joules of energy per seco...

Answered by Henry J. • Physics tutor

3851 Views

If an object of mass 6kg was dropped from a height 35m (initially at rest), how long would it take to reach the ground under free fall?

Free fall == only gravity actingUse one of the SUVAT equations: s = ut + 0.5at²s=35m, u=0 (starts at rest), a=g=9.81ms^-2 (gravitational constant), t=?Through rearranging: t=(2s/a)

Answered by Charlotte A. • Physics tutor

2183 Views

Can you please explain the significance of photoelectric effect?

The photoelectric effect is the emission/removal of electrons, normally, from the surface of a metal. This is done as light is shone on the metal. This is a very useful proof that light can act as a parti...

Answered by Khawaja A. • Physics tutor

5342 Views