A large body of matter with no definite shape.
The SI unit is-kilogram(kg).
Complete Question
The complete question is shown on the first uploaded image
Answer:
The work done by the spring is = 
Explanation:
Force = torque × length
Given
F = 9.13 N
length (L) = 5.91 cm = 0.0591 m [Note 1 m = 100 cm ]
considering the formula above
where k denotes torque

Energy Stored 

The ratio of output force to the input force is generally the mechanical advantage of the machine.
Answer:
50m
Explanation:
Given parameters:
Initial velocity = 20m/s
Acceleration = 4m/s²
Time = 10s
Unknown:
Distance traveled by the rocket = ?
Solution:
To solve this problem use the expression below;
v² = u² + 2as
v is the final velocity
u is the initial velocity
a is the acceleration
s is the distance
final velocity = 0
Insert the parameters and solve;
0² = 20² + 2 x 4 x s
-400 = 8s
s = 50m
Disregard the negative sign because distance cannot be negative.