posted by James on .
A dock worker applies a constant horizontal force of 79.0 N to a block of ice on a smooth horizontal floor. The frictional force is negligible. The block starts from rest and moves 11.0 m in the first 6.00 s.
What is the mass of the block of ice?
*I notice two very common complaints on this site, especially when dealing with Physics and math questions. 1) You showed no work! 2) What kind of math is your course based on?! My answers to both of these are simple. I need help because I DON'T KNOW WHAT I AM DOING....and...it is Algebra based Physics. PLEASE help me!
Use the fact that the work done equals the change in kinetic energy.
F X = (1/2) M V^2
X is the distance moved. F is the force. The final velocity (after 6 seconds)is V. Since it accelerates uniformly, the average velocity 11/6 m/s is half the final velocity.
V = 22/6 = 3.667 m/s
Now solve the first equation for M.
M = 2 F X/ V^2