First slide
Work
Question

A particle of mass 100g is thrown vertically upward with a speed of 5m/s. The work done by the force of gravity during the time the particle goes up is

Moderate
Solution

Using work energy theorem,work done = change in Kinetic energy → Wtotal=ΔKE
i.e. work done by gravity should be equal to change in the kinetic energy of the particle.
Wgravity = (KEfinal-KEinitial) Wgravity = (12mv2final-12mv2initial) 

given mass = 100g ; initial velocity = 5m/s; final velocity = 0; substitute in the above equation


Wgravity = 012×1001000(5)2 =-1.25J
Work done by force of gravity = -1.25J
 

Get Instant Solutions
When in doubt download our app. Now available Google Play Store- Doubts App
Download Now
Doubts App