Hi all. Need guidance for some fundamentals physics.

Hi everyone.
I am self studying for my GCE for the past 6 months now. I have been doing revision for a long time and did some question papers. I have a few problems and hope the people here can guide me. Thank you

Problem 1.
1. The problem statement, all variables and given/known data
A 5.0kg mass is suspended from the ceiling. A horizontal force F is applied to hold the string in position as shown

http://ift.tt/1oi9QJt

Determine the reading of F on the spring balance by using a scale diagram

2. Relevant equations

None

3. The attempt at a solution

http://ift.tt/1qrhioS
Am I doing it correctly?
It doesn’t really make sense to me. I can’t determine the force F. I only have 30degree angle and the weight.

Problem 2
1. The problem statement, all variables and given/known data
A ladder weighing 200N is being held by a man. The man shoulder acts as a pivot. His arm is pushing an upward force F.

http://ift.tt/1oi9QZL

Where could a weight of 150N be hang upon, so that force F do not need to counteract the weight of the ladder

2. Relevant equations
Moment= F x Perpendicular Distance

3. The attempt at a solution
I am not sure if I am understanding it correctly. If I am not wrong, the question is asking me, where can I hang a weight of 150N, so that force F no need to counteract the weight of the ladder. Meaning, assume force F = 0N.

Let the distance be x
Total clockwise moment = total anti clockwise moment
150x = 200*0.5
150x = 100
x = 2/3
= 0.667m.

Therefore it needs to be hang 0.667m away from the pivot or at 3.167m of the ladder.

Am I understanding this correctly?

Problem 3
1. The problem statement, all variables and given/known data

The figure shows 2 terminals M and N of a potential divider connected to a 6V battery. The circuit is connected to a Cathode-ray Oscillator.

http://ift.tt/1qrhggO

(a) Describe in details what happens as the terminal is moved at a uniform speed from N to M.
(b) Draw the final reading of the final trace that is shown the CRO as N is moving towards M.

2. Relevant equations

None

3. The attempt at a solution

(a) As terminal N is moving towards M, there will be an increased in e.m.f, the results in a higher reading on the tracd

(b) http://ift.tt/1oi9SB4
This is my attempt.

Please correct me if I make any mistakes thank you.

Theoretical Problem:
Is the work done the same if I move an object vertically upwards of height 2.0m v.s moving up a ramp at height until it reaches 2.0m?

From what I memorise, they are the same. Am I right? But can someone explain why? I want to understand why.

Thank you!

http://ift.tt/1qrhgx4

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