The Energy is Kinetic Energy.
Kinetic Energy = 1/2*mv², Where m is mass in kg, v is velocity in m/s
Energy is 33750 Juoles, v = 30m/s
1/2*mv² = E
1/2*m*30² = 33750
m = (2*33750) / (30²) Using a calculator
m = 75 kg
Mass of object is 75 kg.
The net force is the total force. Add 4 and 2 together and you get 6. Since 5 N are pushing against it, you subtract that from 6. The net force is 1 N.
Given the index of refraction, n and speed of light in the vacuum, c, we can solve for the speed of light in the transparent substance by the equation below.
n = c / v
where v is our unknown.
Substituting the known values,
1.7 = (3 x 10^8 m/s) / v
The value of v is equal to 1.76 x 10^8 m/s.
For the answer to the question above, this is the maximum displacement, the spring has only elastic potential energy.
spring is constant @ 5 N/m
maximum displacement = 2 cm = 0.02 m
elastic potential energy = 1/2 kx²
= 0.5 x 5 x 0.02²
So the answer would be
= 0.001 Joules