Problem 2: Suppose an elephant has a mass of 2950 kg. How fast, in meters per second, does the elephant need to move to have the same kinetic energy as a 69.5-kg sprinter running at 7.5 m/s?

For exercise, an athlete lifts a barbell that weighs 400 N from the ground to a height of 2.20 m at a constant speed in a time of 1.60 s. What is the metabolic energy, in kJ (kiloJoule)?

7. A 2.5kg block slides along a frictionless surface with a speed of 4 m/s. The blocks slides along until itmakes contact with a spring, compressing the spring 15 cm from its rest length at which point the block ismomentarily at rest. (a) how much energy is stored in the spring? (b) what is the spring constant?

A 50 kg object has 1,800 J of potential energy when it is released and allowed to fall to the ground. At what speed will it hit the ground? Assume negligible frictional forces.

5. (a) What is the energy required to walk 20 km at 5 km/hr? (b) Assuming 5 kcal/g of food, calculate the grams of food needed for the walk.

At what speed does a 1200 kg compact car have the same kinetic energy as a 17000 kg truck going 23 km/h? Express your answer in kilometers per hour

-What is the kinetic energy of a 3000 lb automobile which is moving at 30 mi/h? -An automobile has a speed of 60 mi/h. When the brakes are applied, it slows to 15 mi/h in 4 second. What is its acceleration? how far does it travel during the fourth second? -A 1.5 ton automobile crashed into a wall at a speed of 10 mi/h. The car moved 5.00 in before being brought to rest. What was the average force exerted on the wall by the car.

Determine the energy required to accelerate a 1,155-kg car from 10 to 60 km/h on an uphill road with a vertical rise of 46 m. Please give your answer in kJ.

they asked us to use conservation of mechanical energy concepts for this question

How fast would a(n) 73 kg man need to run in order to have the same kinetic energy as an 8.0 g bullet fired at 400 m/s ?