Answer:
tension in rope = 25.0 N
Explanation:
- Two forces act on the suspended weight. The force coming down is the gravitational force and the upward force by the tension in the rope.
- Since the suspended weight is not accelerating so that the net force will be zero. Therefore the tension in the rope should be 25 N.
∑F = F - W = 0
so
F = W
so tension in rope = F = T = 25 N
Answer:
a

b

Explanation:
From the question we are told that
The mass of the rock is 
The length of the small object from the rock is 
The length of the small object from the branch 
An image representing this lever set-up is shown on the first uploaded image
Here the small object acts as a fulcrum
The force exerted by the weight of the rock is mathematically evaluated as

substituting values


So at equilibrium the sum of the moment about the fulcrum is mathematically represented as

Here
is very small so
and 
Hence

=> 
substituting values


The mechanical advantage is mathematically evaluated as

substituting values


I only know what number 1. is and its Mechanical Energy.
Answer:
1) Mass that needs to be converted at 100% efficiency is 0.3504 kg
2) Mass that needs to be converted at 30% efficiency is 1.168 kg
Explanation:
By the principle of mass energy equivalence we have

where,
'E' is the energy produced
'm' is the mass consumed
'c' is the velocity of light in free space
Now the energy produced by the reactor in 1 year equals

Thus the mass that is covertred at 100% efficiency is

Part 2)
At 30% efficiency the mass converted equals

Answer:
7. free fall -- h. 9.8m/s^2
3. Velocity -- x. 60 km/hr west
6. Acceleration -- d. change in velocity/time
8. Centrifugal -- s. towards the centre
13. Work done --w. Force * displacement
5. Uniform circular motion --j. spin cycle in washer
18. Power -- r. kW an hour
7. g -- a. 10N
hope this helps