Question

A motorcycle of mass 200Kg is moving with a velocity of 90Km/h and it takes 5s to

stop after the brakes are applied. Calculate the force exerted by the brakes on the vehicle.​

Answer 1

Answer:

Given:

Mass of motorcycle,M = 200 kg

initial velocity, u = 90 km/h = 24.3 m/s

final velocity, v = 0 m/s

time taken, t = 5s

To find:

Force exerted on the break

Formula to be used:

1) a = (v - u) / t

2) F = Ma

according to question,

a = (24.3 - 0) / 5 = 4.86 ms⁻²

now, F = 200 x 4.86 = 972 N

PS: Good luck!

Answer 2

Answer :

• – 1000 N

Given Information :

• Mass of motorcycle (m) = 200 kg

• Initial velocity (u) = 90 km/h

• Time taken (t) = 5s

• Final velocity (v) = 0 (since it stops)

Conversion of units :

Converting initial velocity into its SI unit (m/s). To convert km/h into m/s, we multiply the given value with 5/18.

$\longmapsto$ 90 km/h = 90 × $\sf \dfrac{5}{18}$ m/s

$\longmapsto$ 90 km/h = 5 × 5 m/s

$\longmapsto$ 90 km/h = 25 m/s

To calculate :

• Force exerted by the brakes of the vehicle. (F)

Calculation :

We know that,

★ F = ma

• F denotes force
• m denotes mass
• a denotes acceleration

So, we need to calculate the acceleration first.

By using the first equation of motion,

★ v = u + at

• v denotes final velocity
• u denotes initial velocity
• a denotes acceleration
• t denotes time

Substituting values,

→ 0 = 25 + 5a

→ 0 - 25 = 5a

→ – 25 = 5a

→ $\sf \dfrac{-25}{5}$ = a

→ – 5 = a

Therefore, acceleration is – 5 m/s².

Now, we know that :

★ F = ma

Substituting values,

→ F = 200 × (–5)

→ F = – 1000 N

Therefore, force exerted by the brakes on the vehicle is – 1000 N or 1000 N in the opposite direction.