Mechanics | Relativity Answers

A ball is dropped from a height of 60 m. How high abo e the ground will it be when 1/3 of its total energy is Kinetic energy?

A waterfall is 30 meters high, and 10000 kg of water flows over it per second. How much power does this flow generate? If all this power is converted to electricity, how many 100-watt bulb can it supply?

Each of the four engines of a DC airplane develops 7500 horse power when the cruising speed is 240 m/s. How much thrust does each engine produce under these circumstances?

A 15-kilowatt motor is used to hoist an 800 kg bucket of concrete to the twentieth floor of a building under construction to height of 90 m. assuming no energy is lost along the process, how much time is required?

The sun exerts a force of 4 X 10²⁸ N on Earth, and the Earth travels 9.4 x 10¹¹m in its annual orbit around the sun. How much work does the sun does on Earth in the course of one the year?

A graph model shows the force on the hockey when the racket hits the puck in a shot. The disc weighs 160 g and is at rest before hitting. What is the speed of the puck after hitting? Give the answer using km/h

A block of wood weighs 65g in air. A lead sinker weighs 70g in water. The sinker is attached to the wood and both together weighs 65g in water. Find the relative density of the wood.

Hockey, which slides at a speed of 3.5 m/s, is hit in the sliding direction. During the stroke, the racket applies a force of 32 N to the puck for 0.17 seconds. At what speed does the puck move after the stroke? The weight of the disc is 150 g. Use the positive direction marked on the image on the invoice.

A 1-kg object moving at 1 m/s undergoes a one-dimensional elastic collision with a 2-kg object initially at rest. What is the speed of the 1-kg object after the collision?