Question

A truck driver slows down the truck from 66km/h to 30km/h in 10 sec, find the retardation​

Answer 1

Answer:

initial speed(u) = 66km/h = 18.3m/s

final speed(v) = 30km/h = 8.3m/s

time(t) = 10sec

acceleration = (v-u)/t

= (8.3-18.3)/10

= -10/10

= -1m/s²

retardation = - acceleration

= -(-1m/s²)

= 1m/s²

Explanation:

HOPE IT WILL HELP YOU:-)

Answer 2

Answer:

1 m/s²

Explanation:

Given -

Initial velocity (u) = 66 km/h

Final velocity (v) = 30 km/h

Time (t) = 10 sec

To find -

The retardation (negative acceleration)

Solution -

The formula of retardation is same as acceleration = (v-u)/t

But here velocities are in km/h and time is in sec, so we have to change velocities into m/s.

The formula to change km/h to m/s = velocity×5/18

so,

66 km/h = 66×5/18 m/s

= 330/18 m/s

= 18.33 m/s (u)

30 km = 30×5/18 m/s

= 150/18 m/s

= 8.33 m/s (v)

so acceleration = (v-u)/t

= (8.33-18.33)/10 m/s²

= -10/10 m/s²

= -1 m/s²

Because retardation is negative acceleration so -1 m/s² acceleration will be 1 m/s² retardation.

hope it helps.