Question

A block of mass 5.00 kg slides down an incline of inclination 30° and length 10 m. Find the work done by the force of gravity.

Concept of Physics - 1 , HC VERMA , Chapter " Work and Energy"

Answer 1

Hello Dear.

Given ⇒ 
Mass of the block(m) = 5 kg.
Distance covered by the block(S) = 10 m.
Angle of Inclination(θ) = 30°

∵ Force (F) = Mass × Acceleration due to gravity.
∴ Force = 5 × 9.8
∴ Force = 49 N.

Using the Formula,

Work Done by the Force of Gravity = F.S. Sinθ

∴ W = 49 × 10 × Sin 30°
⇒ W = 490 × 1/2   [ ∵ Sin 30° = 1/2]
∴  W = 245 J.

Hence, the work done by the force of Gravity on the block is 245 J.


Hope it helps.

Answer 2

HEY!!

_____________________________

NOTE:- Ia m assuming theta as A

Mass of block, M= 5kg

Angle of inclination = A = 30°

Gravitational force acting on the block, F=mg
Work done by the force of gravity depends only on the height of the object, not on the path length covered by the object.

Height of the object, h = 10× sin30°

10×1/2 = 5m

Work done by force of gravit, W = mgh

5 × 9.8 × 5 = 245j