WORK ENERGY POWER

A body of mass 50 kg is at rest. The work done to accelerate it by 20 m/s² in 10 s is

• 10³ J

• 10⁶ J

• 2×10³ J

• 4×10⁴ J

Find the work done if a particle moves from position r1 = 2i+3k-5j to a position r2= i-2j+3k under the effect of force F= 3i+2j+4k

• 3 J

• 4J

• 5J

• 6J

How much work is done by a coolie walking on a horizontal platform with a load on his head ?

• 0

• 9.8 J

A body of mass 0.3 kg is taken up an inclined plane to length 10 m and height 5 m and then allowed to slide down to the bottom again. The coefficient of friction between the body and the plane is 0.15. What is the work done by the gravitational force over the round trip.

• 0J

• 14.7J

A position dependent force, F = 7 – 2x + 3x² N acts on a small body of mass 2 kg and displaces it from x = 0 to x = 5 m. The work done in joule is

• 135 J

• 270 J

• 35 J

• 70 J