Hard work
Use: g = 10 N/kg
1 A large crane does 120 000 J of work in lifting a load 3 m. Find the weight of the load.
2 Zaneta and her friend Kate are visiting Paris and decide to climb the Eiffel Tower. Zaneta has a mass of 60 kg. She does 180 000 J of work in climbing the 1792 steps to the top of the tower.
a How high is the Eiffel Tower?
b Kate has a mass of 50 kg. How much work did Kate do in climbing to the top of the tower?
3 Calum does 2000 J of work in walking up the stairs of his office building. Calum’s mass is 80 kg.
a How high does he climb?
b How will the amount of work Calum does change if he runs up the stairs? Explain your answer.
4 Ben is driving his car at high speed on the motorway. The car has 400 000 J of kinetic energy. Ben sees a queue ahead, so he applies his brakes to stop the car. The braking force is 6000 N.
a How far does Ben travel while braking?
b Why will he travel further than the distance you have calculated after seeing the queue?
Hard work
Use: g = 10 N/kg
1 A large crane does 120 000 J of work in lifting a load 3 m. Find the weight of the load.
2 Zaneta and her friend Kate are visiting Paris and decide to climb the Eiffel Tower. Zaneta has a mass of 60 kg. She does 180 000 J of work in climbing the 1792 steps to the top of the tower.
a How high is the Eiffel Tower?
b Kate has a mass of 50 kg. How much work did Kate do in climbing to the top of the tower?
3 Calum does 2000 J of work in walking up the stairs of his office building. Calum’s mass is 80 kg.
a How high does he climb?
b How will the amount of work Calum does change if he runs up the stairs? Explain your answer.
4 Ben is driving his car at high speed on the motorway. The car has 400 000 J of kinetic energy. Ben sees a queue ahead, so he applies his brakes to stop the car. The braking force is 6000 N.
a How far does Ben travel while braking?
b Why will he travel further than the distance you have calculated after seeing the queue?