A student gives a brief push to a block of dry ice. A moment later, the block moves across a very smooth surface at a constant s
peed. When drawing the free body diagram for the block of dry ice moving at a constant speed, the forces that should be included are: (select all that apply) a. gravity
b. force
c. force of friction
d. normal force
Question: "<span>A student gives a brief push to a block of dry ice. A moment later, the block moves across a very smooth surface at a constant speed. When drawing the free body diagram for the block of dry ice moving at a constant speed, the forces that should be included are: (select all that apply)"
Your question states: <span>A student gives a brief push to a block of dry ice. A moment later, the block moves across a very smooth surface at a constant speed. When drawing the free body diagram for the block of dry ice moving at a constant speed, the forces that should be included are: (select all that apply)
Your correct answer would be "force of friction" and also just plain "force". The reason why it would just be "force" would be because the student gave a little push to the block of dry ice. This would be the motion of force. Now, the fact that the block continued to move at a constant speed would be because it had a "force of friction" which means that there is a substance that would attract the block of dry ice. That is why the "force of friction" would be your answer. Now, GRAVITY would be involved in this case, the block of ice is already on the ground, this gravity would NOT be your answer.
Let's assume that ground level is the height 0 meters. The change in potential energy is going to be gravitational potential energy, which is given by PE=mgh. ΔPE=mgh-mgy =mg(h-y) =50(28-0) =1400 J
