Mechanics | Relativity Answers

The density of gold is 19.3 g/cm3. A gold dealer advertized a bar of pure gold for sale. The Gold bar has a mass of 3300.00 g and measured 2.00 cm x 15.0 cm x 6.00 cm. Was the bar pure gold

A girl weighing 30kg skips 0.3 meter height 20 times calculate the work done by her

9. A partially filled bag of cement having a mass of 16.0 kg falls 40.0 m into a river from a bridge.
(a) What is the kinetic energy of the bag as it hits the water?
(b) Using energy considerations only, what vertical speed does it have on impact?

During the hammer throw at a track meet, an 8.0 kg hammer is accidentally thrown straight up. If 784.0 J of work were done on the hammer to give it vertical velocity, how high will it rise?

A block weighing 98.0 N falls 64.0 m.
(a) What is the potential energy of the block at 64.0 m?
(b) What speed does the block have as it strikes the ground?

A 15.0 kg object is moving with a velocity of +7.50 m/s. A force of -10.0 N acts on the object and its velocity becomes 3.20 m/s. What is the displacement of the object while the force acts?

A large chunk of ice with a mass of 15.0 kg falls from a roof 8.00 m above the ground.
(a) What is the kinetic energy of the ice as it reaches the ground?
(b) What is its speed as it reaches the ground?

A 450 kg compressor slides down a loading ramp that is 7.0 m long. Initially at rest, the compressor’s speed at the bottom of the ramp is 1.1 m/s. What is the magnitude of the net force acting on the compressor?

A hockey puck with an initial speed of 8.0 m/s coasts 45 m to a stop across the ice. If the force of friction on the puck has a magnitude of 0.12 N, what is the puck’s mass?

A 2.00 × 102 kg iceboat is propelled across the horizontal surface of a frozen lake by the wind. The wind exerts a constant force of 4.00 × 102 N while the boat moves 0.90 km. Assume that frictional forces are negligible and that the boat starts from rest. What is the boat’s final speed?