Question

A force of 100N is applied on an object and the object diceplased to a distance of 8m in 20s then the power of object is
a) 160W
b) 40W
c) 3200W
d) 1000W​

Answer 1

Given :

• Force applied = 100N
• Displacement of object = 8m
• Time taken = 20s

To find :

• Power of object

Formula used :

1. W = F.s
2. P = W/t

Here,

• W = work done
• F = Force applied
• s = displacement of object
• t = time taken
• P = Power of object

Solution :

Firstly we need to find work done by focre in displacing object.

W = F.s

➝ W = (F)(s)(cosθ)

Note - As we have no information about direction of force that [ is (cosθ) ], we will take value of (cosθ) = 1

➝ W = (F)(s)(1)

➝ W = (100N)(8m)

➝ W = 800 Nm

➝ W = 800 J

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Now by using relationship between work time and power we will find power of object.

➝ P = W/t

➝ P = 800J ÷ 20s

➝ P = 40 J/s

➝ P = 40 Watt

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ANSWER :

Option b) 40 Watt