KINETIC ENERGY NUMERICALS (MODERATE LEVEL)

• A ball has a mass of 10 kg; suppose it travels at 100 m/s. Find the kinetic energy possessed by it.
• Work done by a force on a moving object is 100J. It was traveling at a speed of 2 m/s. Find the new speed of the object if the mass of the object is 2 kg.
• Work done by a force on a moving object is -50J. It was traveling at a speed of 10m/s. Find the new speed of the object if the mass of the object is 2 kg.
• Suppose a 1000 kg object was traveling at a speed of 10 m/s. Now, this mass transfers all its energy to a mass of 10 kg. What will be the velocity of the 10 kg mass after being hit by it? 
• Suppose a 10 kg mass was traveling at a speed of 100 m/s. Now, this mass transfers all its energy to a mass of 20 kg. What will be the velocity of the 20 kg mass after being hit by it? 
• Suppose a 10 kg block was kept at a 20m height. Now, this block is dropped. Find out the velocity of the block just before it hits the ground.
•  Suppose a rock of 100 kg was kept at an 80m height. Now, this block is dropped. Find out the velocity of the block just before it hits the ground.
• Calculate the work required to be done to stop a car of 1500 kg moving with a velocity of  60km/h?
• A bullet of mass 15 g has a speed of 400 m/s. What is its kinetic energy? The bullet strikes a thick target and is brought to rest in 2 cm, calculate the average net force acting on the bullet. What happens to kinetic energy originally in the bullet?
•  When loading a truck, a man lifts boxes of 100 N each through a height of 1.5 m. (a) How much work does he do in lifting one box? (b) How much energy is transferred when one box is lifted? (c) If the man lifts 4 boxes per minute, at what power is he working? (g = 10 m s−2 )