Question

Calculate the work required to be done to stop a car of 1500 kg moving at a speed of 72 km/h

Answer 1

Answer:- = 300 kJ

Step by Step Solution:-

We have  given  that the  car  is  moving  with  a particular speed of  72km/h.

So car  have a Kinetic  energy due to its speed. We have  to work against this Kinetic Energy. If we  want  to stop the car, we have to work as equal to its Kinetic Energy in last.

We have,

m = 1500 kg

Initial speed(u) = 72 km/h = 72 × 5/18 = 20 m/s

Final Speed (v) = 0

Using Work - Energy Theorem,

Work done = m/2(u² - v²)

= 1500/2(20² - 0)

= 750 × 400

= 300000 J

= 300 kJ

Answer 2

Bonjour ⚘⚘

Answer:

• 300kj

Explanation:

Given:

• mass of the car = 1500kg
• speed of the car = 72km/h

Need to calculate:

• work done

Calculation:

Through work energy theorem

>> work done = m/2(u²-v²)

>> work done = 1500/2(20²-0²)

>> work done = 750*(400 - 0)

>> work done = 750*400

>> work done = 300000j

>> work done = 300kj