Physics Answers

a beam of particles strikes a wall containing 2x10^29 nuclei per m^3 .each nucleus behaves like a sphere of radius 3x10^-15 m.find the thickness of a wall that exactly half the particles will penetrate without scattering .what thickness would be needed to stop all but one particle in 10^6?

the sun has an orbital speed of about 220kms^-1 around the centre of the galaxy whose distance is 28 000 light years .estimate the total mass of the galaxy in solar masses

In a magnetic field of 14x10^-4 T a 4.2x10^-6 C flows at a velocity of 4x10^6 m/s. The angle is

90 degrees. How strong is the magnetic force operating on the charge?

In the presence of a magnetic field with a strength of 6.0x10^-3T, a 36m long wire carries a

current of 11.0A. Determine the amount of the magnetic force acting on the wire. The angle of

the line is 45 degrees

A rock is thrown horizontally from the top of a cliff 88m high , with a horizontal speed of 24m/s with what velocity does the rock hit and what is the direction of velocity

The number density of copper atoms is 8.49×(10^28) atoms (m^-3). If each atoms contributes one free electrons for conduction, examine whether the electron gas is strongly degenerate at room temperature.

If your heart rate is 182 beats per minute during strenuous exercise, what is the time per beat in units of seconds?

Do not forget the unit

a rock is thrown horizontally from the top of a cliff 88 m high, with a horizontal speed of 25 m/s. with what velocity does the rock hit?

A 2000 kg truck accelerates from 20kph to 120 kph in 10 seconds. Find its engine’s power output in watts. 

1. Air resistance is an example of _____?

A. Gravity

B. Friction

C. Natural motion

D. All of the above