Question

A car travelling at 108km/hr has its speed reduced to 36km/hr in 10sec acceleration is?

Answer 1

let u be the initial velocity,v be the final velocity,t be the time taken and a be the acceleration.

From the definition of acceleration,we know that acceleration is equal to:

(final velocity-initial velocity)/time taken.

a=(v-u)/t

Substituting the values:

u=108km/h=108*5/18=30m/s.
v=36km/h=36*5/18=10m/s.
t=10s

a=(10-30)/10
a=-20/10
a=-2/1
a=-2m/s2

Therefore the acceleration is -2 m/s2.

The negative sign(-) here represents deacceleration or retardation.

i.e.the object is coming to rest.

Answer 2

Hope it's the correct answer