While standing on a frictionless ice surface, a 50 kg skater pushes against a wall with an average force of 150 N west for 0.210 s. Calculate the velocity of the skater at 0.210 s.
This was what i did:
m = 50 kg
Fnet = 150 N
t = 0.210 s
Vf =?
Fnet = ma
Fnet/m = a
150 N/50 kg = 3 m/s^2
a = Vf-Vo/t
at - Vo = Vf
3m/s^2/0.210 s = 0.63 m/s west
Your calculations are correct. By applying Newton's second law (Fnet = ma), you found the acceleration to be 3 m/s^2. Then, using the kinematic equation Vf = Vo + at, where Vo is the initial velocity (which is 0 in this case since the skater starts from rest), and t is the time (0.210 s), you correctly found the final velocity to be 0.63 m/s west.
Well done on solving the problem! Is there anything else I can help you with?