Abus slams on its breaks and goes from 30 km/hr to 15km/hr in 4 seconds. what is its acceleration?

Acceleration is the rate of change of speed.

If the speed is increased then its called acceleration

If the speed is decresed then its a negative acceleration also called deceleration

the formula for calculating acceleration is

where a - acceleration

v - final velocity

u - initial velocity

t - time

v - 15 km/hr should be converted to m/s

distance in 1 hour - 15 km

1 hour = 3600 s

1 km - 1000 m

in 3600 s - 15 000 m

in 1 s - 15 000 m / 3600 s = 4.17 m/s

u - 30 km/hr

in 3600 s - 30 000 m

in 1 s - 30 000 m / 3600 s = 8.33 m/s

substituting the values in the equation

= -1.04 m/s²

the answer is negative means its deceleration

the acceleration is -1.04 m/s²

cross multiplying, we get :

⇒ (3) × (5) = (9) × (x)

⇒ 15 = 9x

step-by-step explanation: