Urgent help needed pls help
Before she starts to coast, Paivi is skating hand in hand with her big brother Panu (mass
60kg). Assuming that Panu also starts coasting from an initial speed of 30 km/h, will he
cover the same distance as Paivi?
Why does the mass not matter why do they travel the same distance

Question

Urgent help needed pls help 
Before she starts to coast, Paivi is skating hand in hand with her big brother Panu (mass
60kg). Assuming that Panu also starts coasting from an initial speed of 30 km/h, will he
cover the same distance as Paivi?
Why does the mass not matter why do they travel the same distance

anonymous · Answer

This is in the league of:
Neglecting air resistance, which falls faster: a feather or a brick?
The acceleration of an object due to gravity does not depend on the mass:
$$g=9.8\frac{m}{s^2}$$
To find the velocity of a falling object as a function of time you can integrate the acceleration:
$$v=\int g dt = gt$$
Again, no mass involved.
The only difference is in the force that is exerted on the objects by the earth according to Newtons second law for gravity:
$$F=mg$$
So the force working on the heavier person is larger, but their acceleration is the same. Is it clear?