Question

starting from a stationary position. Rahul paddles his bicycle to attain a velocity of 6 m/sec in 30 sec. Then he applies brakes such that the velocity of bicycle comes down to is m/ sec in the bicycle in both cases?​

Answer 1

Given that,

Velocity = 6 m/s

Time = 30 sec

Suppose,  the velocity of the bicycle comes down to  is 4 m/s in the next 5 s. Calculate the acceleration of the bicycle in both the cases.

For first case,

Initial velocity = 0

Final velocity = 6 m/s

Time = 30 sec

We need to calculate the acceleration of the bicycle

Using equation of motion

$v = u+at$

Where, v = final velocity

u = initial velocity

a = acceleration

t = time

Put the value into the formula

$6=0+a\times30$

$a=\dfrac{6}{30}\ m/s^2$

$a=0.2\ m/s^2$

For second case,

Initial velocity = 6 m/s

Final velocity = 4 m/s

Time = 5 sec

We need to calculate the acceleration of the bicycle

Using equation of motion

$v = u+at$

Put the value into the formula

$4=6+a\times5$

$a=\dfrac{4-6}{5}$

$a =\dfrac{-2}{5}$

$a=-0.4\ m/s^2$

Hence, The acceleration of the bicycle in both the cases are 0.2 m/s² and  -0.4 m/s².