Answer:

Explanation:
As we know that volume of cylinder is

Where v=volume , h= height or thickness and r= radius
Here,

Putting these values in the previous equation , we get

Therefore thickness is 27.5 m
Answer:
55 kg
Explanation:
Mass does not change and is not dependant on gravity. So even though your weight will be less on the moon your mass won't change.
Answer:
If the starting GPE is doubled than it's KE would also double.
Heat stroke had occurred when your body can no longer regulate its temperature. hope it helps :)
Explanation:
They probably put "rolls without slipping" in there to indicate that there is no loss in friction; or that the friction is constant throughout the movement of the disk. So it's more of a contingency part of the explanation of the problem.
(Remember how earlier on in Physics lessons, we see "ignore friction" written into problems; it just removes the "What about [ ]?" question for anyone who might ask.)
In this case, you can't ignore friction because the disk wouldn't roll without it.
As far as friction producing a torque... I would say that friction is a result of the torque in this case. And because the point of contact is, presumably, the ground, the friction is tangential to the disk. Meaning the friction is linear and has no angular component.
(You could probably argue that by Newton's 3rd Law there should be some opposing torque, but I think that's outside of the scope of this problem.)
Hopefully this helps clear up the misunderstanding for you.