A bus is moving with a speed of 20 m per second after 10 second it applies break and it is top in 5 second find the total distance travelled by the Bus

Question

This is my home work 

Answer 1

Divide the problem into 2 parts:

 

Part (1)

 

d₁ = distance traveled before braking

 

d₁ = v₁t = (20 m/s)(10 s) = 200 m

 

Part (2)

 

d₂ = distance traveled during braking

 

a = braking acceleration, which I assume is constant over the 5s of braking time

 

a = [(0 - 20) m/s]/(5s) = -4 m/s²

 

From kinematics,

 

(0)² - v₁² = 2ad₂ ⇒

 

d₂ = -v₁²/(2a) = -(20²)/[2(-4)] m = 50 m

 

Total distance traveled is

 

d = d₁ + d₂ = (200 + 50) m = 250 m