15 Basic mechanics (2365) (A)

1. If a mass of 500kg is lifted through a height of 2m, calculate the amount of work done.

Answer explanation

Work done=Force×Distance

Force=Mass×Acceleration

∴ Work done=Mass×Acceleration×Distance

Work done= 500×9.81×2

9810 Nm or 9810 Joules

2.A mass of 300kg is raised through a vertical height of 8m. Calculate the amount of work done.

Answer explanation

Work done=Force×Distance

Force=Mass×Acceleration

∴ Work done=Mass×Acceleration×Distance

Work done= 300×9.81×8

23544 Nm or 23544 Joules

3.Calculate the work done when a force of 750N moves an object through a horizontal distance of 15m.

Answer explanation

Work done = Force×Distance

Work done = 750×15

11250 Nm or 11250 Joules

4.Calculate the work done when a force of 350N moves an object through a horizontal distance of 3.5m.

Answer explanation

Work done = Force×Distance

Work done = 350×3.5

1225 Nm or 1225 Joules

5. If the amount of work done by a force of 100N is 800Nm, calculate the distance the object has moved.

6.Calculate the distance covered by a trolley of 51N weight when the amount of work done is 1,020Nm.

7.Calculate the opposition force of a transformer that moves 40m when the work done is 14,000Nm.

8. Calculate the mass of a transformer that moves 25m when the work done is 23,298.75Nm.

9. An object is moved across a distance of 20m in 5 seconds by a force of 50N. Calculate the power used.

10. Calculate the power required to move a weight of 300N through a vertical distance of 5m in 2 seconds.