Answer: Twice the previous time would be taken to reach the same speed v with the puck of mass 2m.
Explanation:
Let a Force pushes the hockey puck of mass m.
Then acceleration, \(a= \frac{F}{m}\)
From the equation of motion,
\(\Rightarrow v=u+at\\ v=0+\frac{F}{m}\Delta t\) ......(1)
In the second case, when mass is 2m, then acceleration,
\(a'=\frac{F}{2m}\)
and t' is the time taken.
The final speed is v,
\(\Rightarrow v=0+ a't'\\ \Rightarrow \frac {F}{m}\Delta t=\frac{F}{2m}t'\\ \Rightarrow t'= 2\Delta t\) using equation (1)
Hence, it would take two times the previous amount of time to push the pluck of double mass.