Question

calculate the work done to move a car of 3000 kg on a frictionless road for 500m from its start to attain 40km/h in 2 minutes. meritnation

Answer 1

Hii friend,

Here is your answer...

Hope this helps you a little!!!

Answer 2

$\red{\mid{\underline{\overline{\textbf{Answer}}}\mid}}$

Work done = 1.38 × 10^5 J

$\red{\mid{\underline{\overline{\textbf{Explanation}}}\mid}}$

Work is said to be done when a force is applied on a body and the body undergoes displacement.

It is measured in Joules. It is represented by the expression :

$\bigstar \: \orange{\mid{\underline{\overline{\textbf{w = f×s}}}\mid}}$

In this equation :

• w = work done
• f = force applied
• s = displacement or distance

$\blue{\mid{\underline{\overline{\textbf{Coming to question :-}}}\mid}}$

In this question we have been given the mass of body which is moving on a frictionless surface of 500m with speed of 40km/h and moved for 2minutes. Work done on body is not known , we have to calculate it.

It is given that :

1. Mass of body = 3000kg
2. Lenght of road = 500m
3. Velocity = 40km/h = 40× 5/18 m/s
4. Time for which travelled = 2mins = 120secs.

Now, if we talk about the acceleration of body them it is rate of change of velocity, since body is frictionless then the body will never stop.

Now it's acceleration will be = Initial velocity / Time in this case .

$\mapsto \: a = \frac{40 \times 5}{120 \times 18}$

Leaving the acceleration in expanded form here will help us in Calculations in future.

Now the worm done on car is = F × s

where F = ma,

After inputting the values in this equation we get:

$\mapsto \: w= \frac{3000 \times 40 \times 5}{120 \times 18} \times 500m \\ \\ \mapsto \: w = \frac{3000 \times 5 \times 500}{18 \times 3}$

$\mapsto \: w = \: \cancel \frac{3000}{3} \times \frac{5 \times 500}{18} \\ \\ \mapsto \: w = \frac{1000 \times 5 \times 500}{18}$

$\mapsto \: w= \frac{2500000}{18} \\ \\ \mapsto \: w = 1.38 \times {10}^{5} joule$

Therefore work done is 1.38 × 10^5 J.

______________________________________

BY SCIVIBHANSHU

THANK YOU

STAY CURIOUS