Physics Question

Question

A hockey player uses her hockey stick to exert a force of  N on a stationary hockey puck, which is resting on a nearly frictionless ice surface. The hockey puck has a mass of  g. What is the acceleration of the hockey puck?

Answer 1

Since the question contains mixed units meaning units from two different systems, we must first convert one or the other so the units are consistent. In such cases, it is far easier to convert all units to SI rather than trying to convert to some other system.

Force = 4.36N

mass = 155g (CGS system) in SI mass is expressed in kg [1000g=1kg]

∴ 155g=1kg/1000g gives us 155/1000kg or 0.155kg

Now, we know that net force F=m x a

rearranging, we have a=m/F

or a=0.155kg/4.36kgms^-2 (since N=khms^-2)

i.e. a=0.0356ms^-2 (3 sig fig)

I hope this is clear, but if you have more questions about this or other problems, pleae feel free to ask me.