U2.9 – Work, Power & Energy

Select the SI unit for Power.

Select the SI unit for Work.

Select the SI unit for Energy.

A bungee jumper of mass 74 kg, falls 68.5 m before the bungee cord begins to stretch. Calculate the gravitational potential energy lost by the bungee jumper in falling 68.5 m. g = 9.81 Nkg^-1.

The Shenzhou (Chinese: 神舟) re-entry capsule has a of mass 7840 kg falling through the atmosphere at a steady velocity of 1.75x10⁴ Mph. Calculate its kinetic energy. g = 9.81 ms^-2, 1 Mile = 1.6 km

A crane lifts a Rolls-Royce Trent 1000 engine into place. The engine has a mass of 5,936 kg and is lifted vertically 10 m by the crane in 12 seconds. Calculate the power of the crane. g = 9.81 Nkg^-2.

The Space Shuttle has a mass of 2.03x10⁶ kg. Upon launch, it has two Solid Rocket Boosters (SRB) providing 12,000 kN of thrust in 123 s. It uses the SRB's to ascend to an altitude of 46 km before jetsoning them. Calculate the Space Shuttle's velocity. Ignore any change in mass due to spent fuel. g = 9.81 ms^-2

The Soyuz (Russian: Сою́з) descent module, of mass 2900 kg, re-enters the atmosphere at an angle of 1.35° to the horizontal, and travels 4200 km until it reaches 10.7 km before deploying it's parachutes. Calculate the change in E_g from the point of atmospheric re-entry to parachute deployment.

The diagram shows a swing 1.43m long. Matilda has a mass of 35 kg and is released from rest at position A by Miss Honey. Calculate the speed of Matilda at position B.

A VW campervan cruises along a straight, flat Autobahn at a speed of 130 kmh^-1. The total resistive force, due to air resistance, is 900 N.

If the overall efficiency of the campervan is 18%, calculate the energy obtained from its fuel during 42 km journey.