Exercise work and energy 2
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1. The document contains 9 problems involving calculating work, power, and energy. The problems include calculating the work done by different forces moving objects over distances, lifting objects vertically, and exerting forces over time. 2. Specific calculations involve determining the work done by forces pushing objects like pencils and sandwiches, as well as lifting bags and pushing people in wagons or on sleds. 3. The final problem involves calculating the work done by a boy dragging a wagon full of newspapers over time using a specific force.
Exercise work and energy 2
- 1. EXERCISE-2 WORK, POWER, AN D ENERGY
- 2. 1. Calculate the work done by a 47 N force pushing a pencil 0.26 m. 2. Calculate the work done by a 47 N force pushing a 0.025 kg pencil 0.25 m against a force of 23 N. 3. Calculate the work done by a 2.4 N force pushing a 400. g sandwich across a table 0.75 m wide. 4. How far can a mother push a 20.0 kg baby carriage, using a force of 62.0 N at an angle of 30.0º to the horizontal, if she can do 2920 J of work? 5. How much work is it to lift a 20. kg sack of potatoes vertically 6.5 m?
- 3. 6. If a small motor does 520. J of work to move a toy car 260. m, what force does it exert? 7. A girl pushes her little brother on his sled with a force of 300. N for 750. m. How much work is this if the force of friction acting on the sled is (a) 200. N, (b) 300. N? 8. A 75.0 kg man pushes on a 5.0 x 105 ton wall for 250 s but it does not move. How much work does he do on the wall? (2000 lb = 1 ton; 0.454 kg = 1 lb) 9. A boy on a bicycle drags a wagon full of newspapers at 0.800 m/s for 30.0 min using a force of 40.0 N. How much work has the boy done?