Question

A car start from rest and acquire a velocity of 54 km/h in 2 sec. Find



(i) the acceleration



(ii) distance travelled by car assume motion of car is uniform?



answer

Answer 1

Answer:

1) acceleration = 7.5m/s²

2) distance travelled = 15m

Explanation:

Given that a car starts from rest

so,

initial velocity will be 0

in 2 seconds it acquires a velocity of 54km/h

= 54000m/3600s

= 540m/36s

15m/s

so,

now, it's given that

initial velocity(u) = 0m/s

final velocity(v) = 15m/s

time(t) = 2 s

so,

acceleration = v - u

t

= 15/2 m/s²

= 7.5m/s²

now,

if motion is uniform

then distance(s) travelled in 2 seconds =

s = ut + 1/2at²

= 0×2 + 1/2 × 7.5 × 2 × 2

= 15m

Answer 2

Answer: acceleration = 7.5m/s2

distance travelled = 15m

Explanation:

Given that

Initial velocity, u = 0m/s

Final velocity,v = 54 km/ h

                        =15m/s

time, t = 2 sec.

we know that

a = v - u/ t

= 15 - 0 / 2

=15/2

=7.5m/s2

then distance travelled,

s = ut + 1/2 *at2

  = 0*2 + 1/2* 7.5*2*2

 =15m

HOPE IT HELPS YOU!