Answer:
first one i think is this. work = 1/2 kx^2 = 1/2 Fx
2nd, is 0.08 J
Explanation:
EE = ½ kx²
EE = ½ (400 N/m) (0.02 m) ²
EE = 0.08.
THIRD, Velocity of the stone is 4 m/s when it leaves catapult.
Answer:
1.147 %
Explanation:
= Density of mercury = 
g = Acceleration due to gravity = 9.81 m/s²
h = Height of mercury = 8.69 m
Standard atmospheric pressure = 
6.55 mmHg converting to Pa

Dividing air pressure by the above value

The fraction of atmospheric pressure is 1.147 %
Answer:
the car’s final displacement is 60 m
Explanation:
Given;
initail velocity of the car, u = 0
acceleration of the car, a = 0.8 m/s²
time of motion, t = 10 s
The first displacement of the car:

The second displacement of the car;
acceleration, a = 0.4 m/s², time of motion, t = 10 s

The final displacement of the car;
x = x₁ + x₂
x = 40 m + 20 m
x = 60 m
Therefore, the car’s final displacement is 60 m