Question

A car of mass 2000kg changes its speed from 72km/h to 36km/h in 5seconds. The force Applied by its brake is

Answer 1

Answer:

-4000 Newtons

Explanation:

Given :

• Mass of the car = 2000 kg

• Initial velocity of the car = 72 km/h

• Final velocity of the car = 36 km/h

• Time taken = 5 seconds

To find :

• Force applied by the brakes

Force = mass(v-u) /t

v = 36 km/h = 36×5/18 = 10 m/s

u = 72 km/h = 72×5/18 = 20 m/s

Force = 2000(10-20)/5

Force = 2000(-10)/5

Force = - 20000/5

Force = - 4000 Newtons

The force applied in the direction of car is - 4000 newtons

Answer 2

Answer:

Given:

• A car of mass 2000kg changes its speed from 72km/h to 36km/h in 5seconds.

Find:

• Find the force Applied by its brake

Know terms:

1. Initial Speed = (u)
2. Final Speed = (v)
3. Acceleration = (A)
4. Time = (T)
5. Mass = (M)
6. Charge of velocity = (V)

Using formula:

☆ ${\sf{\underline{\boxed{\orange{\sf{A = \dfrac{V}{T} }}}}}}$

Calculations:

⇒ $\bold{A = \dfrac{10 - 20}{5}}$

⇒ $\bold{A = \dfrac{-10}{5}}$

⇒ ${\sf{\underline{\boxed{\red{\sf{A = -2 \: m/s^2 }}}}}}$

☆ ${\sf{\underline{\boxed{\orange{\sf{Force \: applied = M \times A}}}}}}$

⇒ $\bold{2000 \times 2}$

⇒ ${\sf{\underline{\boxed{\red{\sf{4000 \: N }}}}}}$