Question

Calculate the work done by a bicycle
of mass 20 kg
in increasing
its speed from 2 ms-1
to 5 ms-1​

Answer 1

Explanation:

We know that whenever work is done, an equal amount of energy is used up. So, the work done in this case will be equal to the change in kinetic energy of bicycle when its speed changes from 2 m/s to 5 m/s. Now, Work done = Change in kinetic energy. Thus, the work done is 210 J.

Answer 2

Explanation:

m=20kg

velocity u=2m/s

velocity v =5m/s

:.work done =force × displacement

w= f×s

w=mass×s (a=acceleration of the bicycle)

v^2=u^2+2aS

=>2aS=5^2-2^2

=>aS=25-4/2

=>aS=21/2

=>aS=10.5m^2/sec.square

w=m×(aS)

w=20×10.5

w=210 joules

answer->210 joules