Question

*1. Starting from rest a bike attains 36 km/h in 10 second. Find distance travelled during this time.*
*2. Find average velocity in q no 1 above and from that find distance covered.*​

Answer 1

Answer:

Given

v=36kmh

−1

=

3600

36000

=10ms

−1

s=9km=9000m

This motion is in three phases.

[Case: 1]

with acceleration, a=0.2ms

−2

and intial velocity , u=0

Thus using equation v=u+at

10=0+0.2×t

So, t=50 s

[Case: 2]

uniform motion with velocity ,v=10

and distance, s=9000

Thus time , t=

v

s

=

10

9000

=900 s

[Case: 3]

With acceleration, a=−0.1ms

−2

u=10ms

−1

and v=0

Thus using equation v=u+at

0=10−0.1×t

So, t=

0.1

10

=100 s

Therefore

Total time = 50s+900s+100s=1050s

So, option A is correct.