Answer:
7. Your answer is correct dear, just add the unit
8. answer is 1.17m/s²
Explanation:
queation 7.
m = 3kg, F = 9N, a ?
F = ma
a = F/m = 9/3 = 3m/s²
Use the same approach for question 8
Answer:

Explanation:
We use the kinematics equation to solve this question:

because the ball is dropped
the acceleration is the gravity, negative because it points downwards
initial height
final height
So:


Work = force * distance.
We must produce twice as much energy as we are lifting the weight twice as high.
But we are not increasing the force so we must increase the length of the ramp ( distance ) instead.
The new length will be twice as great as the previous length.
So 8 metres is required.
25 kg * 8 m = work = 100 kg * 2 m
Work= force x distance
work= 750 x 2
work =1500
power =work/time
power= 1500/ 0.3
power= 5000W
answer: b. 5000W