Question

Starting from rest on a level road a girl can reach a speed of
5 m/s in 10s on her bicycle. Find
a the acceleration,
b the average speed during the 10 s,
c the distance she travels in 10 s.
Eventually, even though she is still pedalling as fast as
she can, she stops accelerating and her speed reaches a
maximum value. Explain in terms of the forces acting why
this happens.​

Answer 1

$\huge{\bold{\underline{\sf{ANSWER}}}}$

$\bigstar\sf{GIVEN}\bigstar$

• $\sf\blue{Initial\:Velocity= 0m/s.}$

• $\sf\red{Final\:velocity=5m/s}$

• $\sf\red{Time=10s}$

$\bigstar\sf{TO\:FIND}\bigstar$

• $\bigstar\text{Acceleration produced by car}\bigstar$

$\sf\bigstar\pink{FORMULA\:USED}$

• $\huge\tt\blue{a=\dfrac{v-u}{t}}$

• $\huge\tt\blue{S=ut+\dfrac{1}{2}×a(t)^2}$

Now,

A=?

Using the given amd first equation of motion

$\implies\sf{A=\frac{5-0}{10}}$

$\implies\sf{A=\frac{1}{2}=0.5m/s^{2}}$

Hence, The acceleration produced by Cycle is 0.5m/s^2.

Now,

Distance=?

$\huge\tt\blue{S=ut+\dfrac{1}{2}×a(t)^2}$

$\implies\sf{S=0×5+\dfrac{1}{2}×0.5×100}$

$\implies\sf{S=0+100}$

$\implies\sf{S=100m}$

Now,

Average speed of Bicylce=?

Average speed= Total Distance travelled/Total time taken

$\implies\sf{\dfrac{100}{10}}$

$\implies\sf{10m/s^{-1}}$