# I want question no. 6 and 7 and their subquestion full Pls send fast Dear Student,

VI) 1) 1. When θ is acute (<90), cosθ is positive. Hence work done is positive.

example: when a body falls freely under the action of gravity.

cos0 = 1. therefore work done by the gravity on the body falling freely is +ve.

2. When θ is acute (>90), cosθ is -ve. Hence work done is -ve.

example: when a body is thrown up, its motion is opposed by the gravity. the angle θ b/w gravitational force and displacement is 180. cos 180 = -1,  therefore work done by the gravity on a body moving upward is -ve.

3.

when, θ = 90

cos90 = 0

work done is said to be zero.

example: when a body tied to one end of a string is rotating in a circle, work done by the centripetal force applied along the string is zero because

θ = 90

cos90 = 0

2) let mass of light body be 'm' & heavy body be 'M'

given that  mV=Mv

We know that K E=p2 /2m

since as p is constant K E is inversly proportional to the mass of the object

hence light body has greater kinetic energy