Question

starting from rest, Nikita paddles her bicycle to attain a velocity of 5 metre per second in 25 seconds. then he applies brakes so that the velocity of bicycle come down to 4 meter per second in the next 5 second. calculate the acceleration of bicycle in both the cases. ​

Answer 1

Answer:

a1=0.2. a2=-0.2

Explanation:

starting from rest so intial speed of bicycle is 0.

now she paddles to attain speed of 5ms.

then by v=u+at

5=0+a(25)

a=5/25

a=1/5

a=0.2 m/s2. (first case)

now brakes are applied so v becomes 4 m/s

so 4=5+a(5)

a=-1/5

a=-0.2m/s2

As its deaccleration or braking accelaration is negative

Answer 2

Answer:

In first case u=0 and v=5m/s and t=25 secs

then a=v-u÷t

=> 5-0÷25=5÷25=1÷5=0.2m/s^2.

In second case u=5m/s and v=4m/s and t=5m/s

then a= v-u÷t

=4-5÷5=(-1) ÷5=-0.2m/s^2