Question

A person moves trolley first up, then down a hill. It is possible to pull or push the trolley on each occasion. With the help of vector diagrams explain which method, pull from above or push from below, is easier in each case.
(Interpret “easier” as meaning “requires the smaller force” and assume that the person is about twice the height of the trolley).

Answer 1

Okay. But you only answer uphill.
How about downhill scenario?

Answer 2

No it's not. Look at the vertical components!

Answer 3

You still drawing the uphill.

Answer 4

So uphill -> pull; downhill ->push?

Answer 5

No. I think you're wrong. The correct one is pull from above in each case. On the downhill scenario, if a person takes position A (push), she has to push to counter force of gravity. This push has down vertical component force relative to the hill. Therefore it creates additional normal force.
\( N=mg+A_x \)

Position B (pulling) on the other hand, have upward vertical component. Thus
\(N= mg-B_y \)

Answer 6

I meant position A (pushing to counter gravity)
\( N=W_y +A_x \)
whereas position B (pulling to counter gravity)
\( N=W_y -B_x \)

Answer 7

I understand your graph precisely.

Answer 8

THERE IS NO F*KING FRICTION ON THE ROLL OF THE F*KING TROLLEY. LOL.
Friction only applies to the things that don't roll.

Answer 9

Such friction are negligible. If you really want to nitpick, okay.
Less normal force create less friction on the wheel, less pressure.

Answer 10

Besides, the wheel of trolley is not rubber, kid.

Answer 11

You are one of those pompous fools, aren't you?
Guys who are fools and covering it all over when their mistakes are pointed out. Che.

Answer 12

@twitter i like it :)

Answer 13

@twitter i would like to explain you one thing , i believe you have incomplete knowledge of friction when you said "THERE IS NO F*KING FRICTION ON THE ROLL OF THE F*KING TROLLEY. LOL. Friction only applies to the things that don't roll.", haven't you heard about ROLLING FRICTION @demitris ..you are right :)

Answer 14

@experiment @mukushla @unklerahkus @mikael @henpen @Jemurray3 look at the comment of @twitter and if she thinks she is so smart (which probably she is not, you are even most pompous) so kindly let her know does she have authority to state what she has stated @mattfeury

Answer 15

@unklerahukus

Answer 16

Really, let this argument lie. I have no interest as to the relative intelligences of anonymous people on the internet.