Question

A car of mass 1800 kg, moving with a speed of 10m/s is brought to rest after
Covering a distance of 80m calculate the force action on the car?​

Answer 1

Given :-

• A car of mass 1800 kg, moving with a speed of 10m/s is brought to rest after covering a distance of 80m

To find :-

• The force action on the car.

Solution :-

• Mass of car (m) = 1800kg

• Initial velocity (u) = 10m/s

• Final velocity (v) = 0

• Distance covered (s) = 80m

According to third equation of motion

→ v² = u² + 2as

→ (0)² = (10)² + 2 × a × 80

→ 0 = 100 + 160a

→ 160a = - 100

→ a = - 100/160

→ a = - 0.625m/s²

Hence, acceleration of car is - 0.625m/s²

As we know that

→ Force = mass × acceleration

→ F = m × a

→ F = 1800 × (-0.625)

→ F = - 1125 N

• Force will be acting in the opposite direction

Therefore,

• The force action on the car is - 1125 N

Answer 2

Given : A car of mass 1800 kg, moving with a speed of 10m/s is brought to rest after covering a distance of 80m.

　

To find : Calculate the force action on the car?

　

Using formula :

★ v² - u² = 2as.

★ F = M (a).

　

Calculations :

→ 0 - (10)² = 2a (80)

→ a = -100/160

→ a = -0.625 m/s² (Deceleration)

　

→ F = 1800 (-0.625)

→ F = -1,125N

　

Therefore, the force action on the car is -1,125 N.