Answer:
The pulling force that the man should apply to create an upward acceleration of 
is 
Explanation:
Hi
As it shows in the drawing at the end, we have that the total mass of the man plus the platform is 
, then the force downward 
is 
.
Due the man needs to do a pulling force upward capable of lifting himself and the platform with an acceleration of , this force should create an acceleration greater than gravity by . then 
. Therefore the force should be 
.
Finally, as we have a pulley arrangement connected to the platform, it gives the man a mechanical advantage, so he has to do only half of that upward force
, therefore 
.
32f. That's because the force is directly proportional to the product of the masses and inversely proportional to the square of the distance. So you get 2•(1/1/4)^2=2•16=32
Answer: E.
Explanation: because the book is on the table, its not really moving in any direction.
Answer:
Mass is how much space the object takes up and how much it has inside, and weight is how heavy the object is.
Explanation: Hope this helps ;)
Output can not be greater than input because the conversion of energy can not be greater than 100%.
