Mechanics | Relativity Answers

A person riding a bicycle is going uphill at 8 m/s. What is the kinetic energy of the system if the total mass of the person and his bicycle is 10.0 kg?

A 100 kg wooden crate is at rest on a level stone floor. If the coefficient of static friction is 0.5. what is the minimum horizontal force needed to get the box moving

Is sitting on a chair considered work

A body with mass 600 kgis located on a 30 degressinclined plane. Calculate the pulling force without friction.

take g = 9.8m/s²

Ariel dropped a golf ball from her second story window. The ball starts form rest and hits the sidewalk 1.5 seconds later with a velocity of 14m/s. Find the avarage acceleration of the golf ball

a diver of mass 80kg,steps off a diving board at point a 4,0 m above the level of the water of a swimming pool.the diver enters the water at point b and comes to rest at point c.while the diver falls through the air,an average frictional force of magnitude 172n acts on the diver. the total work done on the diver by no conservative forced while he moves from a to c is -6240j

A particle travels at 1.90×10⁸ m/s and lives 2.10×10⁻⁸ s when at rest relative to an observer. How long does the particle live as viewed in the laboratory?

c = 3.0×10⁸

If astronauts could travel at v=0.950 c, we on Earth would say it takes 4.42 years to reach Alpha Centauri. The astronauts disagree.

 How much time passes on the astronauts' clocks?

c = 3×10⁸