Question

Explain this question and answer also​

Answer 1

Answer:

Given :

An object undergoes oblique projectile motion

To find:

Work done by gravitational force

Concept:

Work done is always calculated as the Scalar product (dot product) of force and displacement.

W = F . d = F × d × cos (θ)

where F is force, d is displacement,

θ is the angle between force and displacement.

Calculation:

Horizontal work done is zero because angle between force (gravity) and displacement is 90 °

Vertical work done is also zero as vertical displacement ( since the object starts from ground and ends on ground) is zero.

Answer 2

Question :-----

• An object thrown at a certain angle to the ground moves in a curved path and falls back to the ground. The initial and the final points of the path of the object lie on the same horizontal line. what is the work done by the force of gravity on the object ?

Solution :----

work done = m*g*h

since it is given that differnce between initial height and final position is zero .

In simple words we can say that both initial and final position lie on same horizontal line,so there is no vertical displacement that means height is 0.

so,

work done = m*g*(h2-h1)

work done = m*g*0

work done = 0 ..

⛬ work done by the force of gravity and against the force of gravity are both equal to 0...

(Hope it helps you)