Question

car decreases its velocity from 36 kilometre per hour to 18 km per hour in 5 second find the acceleration of the bus in metre per second square​

Answer 1

Answer:

the acceleration  of the car is equal to $-1 \ m/s^{2}$

Explanation:

Given:

Initial velocity of car = u = 36 km/h

$36 \ km/h =36 \times \frac{5}{18} = 10 \ m/s$

Final velocity of car = v = 18 km/h

$18 \ km/h =18 \times \frac{5}{18} = 5 \ m/s$

Time = 5 seconds

To find:

Acceleration

Acceleration = $\frac{v-u}{t}$; where v = final velocity, u = initial velocity and t = time

Substituting the values, we get:

Acceleration = $\frac{5-10}{5}$

Acceleration = $\frac{-5}{5}$

Acceleration = $-1 \ m/s^{2}$

The acceleration of the car is equal to $-1 \ m/s^{2}$ and hence the car decreases its speed slowly

Answer 2

Answer:

Explanation:

Given :-

Initial velocity of car or bus, u = 36 km = 36 × 5/18 = 10 m/s

Final velocity of car or bus, v = 18 km = 18 × 5/18 = 5 m/s

Time taken by car or bus, t = 5 seconds

To Find :-

Acceleration of car or bus.

Formula to be used :-

1st equation of motion, v = u + at

Solution :-

Putting all the values, we get

v = u + at

⇒ 5 = 10 + a × 5

⇒ 5 = 10 + 5a

⇒ 5 - 10 = 5a

⇒ - 5 = 5a

⇒ - 5/5 = a

⇒ a = - 1 m/s²

Hence, the acceleration of the bus or car in m/s² is  - 1 m/s².

Here negative signs refers to deceleration.