Question

Calculate the work required to be done to stop a car of 1500 kg moving at a velocity of 60 km/h ?​

Answer 1

12495 Joules

Explanation:

Given:-

• Mass ,m = 1500 Kg

• Velocity ,v = 60km/h

To Find:-

• Work Done ,W

Solution:-

Conversion of Velocity in m/s

→ 60km/h = 60 × 5/18 = 300/18 = 16.66 m/s

Here the work done of body is equal to the Kinetic Energy of the object.

• W = KE = 1/2mv²

Where,

KE is the Kinetic Energy

m is the mass

v is the velocity

Substitute the value we get

→ KE = 1/2×1500 × 16.66

→ KE = 750 × 16.66

→ KE = 12495 J

1000 J = 1 KJ

Therefore, 12495 J = 12495/1000 = 12.495 KJ

Therefore, the work done by the body to stop car is 12495 Joules .

Answer 2

Answer:

Given :-

➙ A car of 1500 kg moving at a velocity of 60 km/h.

To Find :-

➙ How the work required to be done .

Formula Used :-

K.E = $\dfrac{1}{2}$mv²

Solution :-

Given :-

» Mass (m) = 1500 kg

» Velocity (v) = 60 km/h = 16.66 m/s

Substituting the formula we get,

↪ K.E = $\dfrac{1}{2}$ × (1500)(16.66)

↪ K.E = 750 × 16.66

↪ K.E = 12495 J

We, know that, 1000 J = 1 kJ

Hence, 12495 J = $\sf\dfrac{\cancel{12495}}{\cancel{1000}}$

➡ 12.495 kJ

$\therefore$ The work required to be done is 12.495 kJ .