Question

A car of mass 900 kg is travelling with a velocity of 10m/s. When brakes are applied it stops after travelling a distance of 10m. Find retarding force

Answer 1

Answer:

Explanation:

Solution,

Here, we have

Mass, m = 900 kg

Initial velocity, u = 10 m/s

Final velocity, v = 0 m/s

Distance covered, s = 10 m,

To Find,

Force, F = ?

According to the 3rd equation of motion,

we know that

v² - u² = 2as

⇒ (0)² - (10)² = 2 × a × 10

⇒ 100 = 20a

⇒ 100/20 = a

⇒ a = 5 m/s²

Here, acceleration is 5 m/s².

Now, we know that,

By Newton's 2nd law,

F = ma

⇒ F = 900 × 5

⇒ F = 4500 N

Hence, the force is 4500 N.

Answer 2

Answer:

Solution,

Here, we have

Mass, m = 900 kg

Initial velocity, u = 10 m/s

Final velocity, v = 0 m/s

Distance covered, s = 10 m,

To Find,

Force, F = ?

According to the 3rd equation of motion,

we know that

v² - u² = 2as

⇒ (0)² - (10)² = 2 × a × 10

⇒ 100 = 20a

⇒ 100/20 = a

⇒ a = 5 m/s²

Here, acceleration is 5 m/s².

Now, we know that,

By Newton's 2nd law,

F = ma

⇒ F = 900 × 5

⇒ F = 4500 N

Hence, the force is 4500 N.

Explanation: