Mechanics | Relativity Answers

what is the kinetic energy of a 3-kg object moving at 7 m/s ?

A raft is constructed of wood having a density of 452.0 kg/m3. The surface area of the bottom of the raft is 5.4 m2, and the volume of the raft is 0.51 m3. When the raft is placed in fresh water having density 1.0 103 kg/m3, how deep is the bottom of the raft below water level?

a gun fires a bullet of mass 50 gms. the bullet moves with a velocity of 100m/sec strikes a wooden plank and comes to rest on 0.05 seconds. calculate the force exerted by the wooden plank on the bullet

weight of a body in earth 9.8 newton. mass will be?????

on a 40km bike ride a cyclist rides the first 20km at 20km/h. what is the speed require for the final 20km if the average speed for the trip is to be 10km/h?

Hi,
I need help with a momentum question. Here it is: Your spacecraft is travelling forward with a momentum of 4940 kgm/s. The space station is 40 degrees to the right. The thrusters on the spacecraft exert a force of 1112 N perpendicular to the motion. How many seconds should you turn the thruster on to change your heading to reach the station? I'm comfused and any help would be appreciated. Thanks.

A concrete block with a mass of 47.02kg is to be pushed along a level floor. The force needed for constant velocity is 28.2 N and the coefficient of kinetic friction is 0.0610116774619834, what force will be needed to accelerate the block at 19.49 m/s/s?

A sled is moving at a constant speed down a surface inclined at 45.0° with the horizontal and travels 30 meters in 4 seconds. Calculate the vertical velocity of the sled at the end of 4 seconds

A man weighs himself inside a lift. He weighs 72kg-wt when the lift goes up with a constant acceleration ‘a’ , while he weighs 69kg-wt when the lift goes down with the same acceleration. The mass of the man is?

assuming no sliding and that the shoulder is 1.2m from the feet,what force is reqiuered to topple a 70 kg person standing with his feet spread 0.9 m? and can i have an explination for the answer?..thanks