NEET Physics Question - Work Energy and Power

A bullet of mass 10g is fired horizontally with a velocity 1000 ms^–1 from a rifle situated at a height 50m above the If the bullet reaches the ground with a velocity 500 ms^–1, the work done against air resistance on the bullet is : (g = 10 ms^–2)

5005 J

3755 J

-3755 J

-5005 J

Solution:

From Work Energy Theorem,

Total Work Done = Change in Kinetic Energy

Work Done by Gravity + Work Done by Air Resistance = ½m (V_f² - V_i² )

0.001 × 10×50 + Work done by Air Resistance = ½× 0.001×( 500² - 1000²)

Solving We get, Work Done by Air Resistance = - 3755 J

Rankers Physics

Solution:

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