Question

9. A girl take a bucket of 10 kg water on level track with
uniform velocity from the stream on her way to home
1 km away from the stream. The work done by her on
the track is
a. 10 Joule
b. 0 Joule
c. 98000 Joule
d. None​

Answer 1

Answer:

(b)0 joule

Explanation:

Think so .Take it

Answer 2

B) 0 Joules of the work has been done

Step-by-step Explanation:

Given: mass $\text{m = 10 kg}$, displacement $\text{s = 1 km = 1000m}$, velocity is uniform

To Find: Work done by the girl on the track

Solution:

• Finding the work done by the girl

Work done by a body is given by;

$\text{W} = \vec{F} \cdot \vec{s} = Fs \ cos(\theta)$

The direction of the displacement and the force is the same, which implies that $\theta = 0$

Thus, $\text{W} =Fs$

But, the force $F$ is the product of mass $m$ and acceleration $a$

$\Rightarrow F = ma = m \frac{dv}{dt}$

For a uniform velocity, the term $\frac{dv}{dt}$ is zero. Therefore, the force $F = 0$

Thus, $\text{W} =Fs = 0$

Hence, the work done by the girl on the track is 0 Joules.