Answer:
Work done by the spring is negative
Explanation:
We can answer this question by thinking what is the force acting on the box.
In fact, the force acting on the box is the restoring force of the spring, which is given by Hooke's Law:

where
k is the spring constant
x is the displacement of the box with respect to the equilibrium position of the spring
The negative sign in the equation indicates that the direction of the force is always opposite to the direction of the displacement: so, whether the spring is compressed or stretched, the force applied by the spring on the box is towards the equilibrium position.
The work done by the restoring force is also given by

where
F is the restoring force
x is the displacement
is the angle between the direction of the force and the displacement
Here we know that the force is always opposite to the displacement, so

Which means that the work done by the spring is always negative, since the direction of the restoring force is always opposite to the direction of motion.
It becomes thermal energy
this heat is produced by tiny particles moving within an object
Answer:
0.6 A
Explanation:
As the motor gears towards full speed, the voltage of the circuit tends to become the difference that exists between the line voltage and the that of the back emf. Remembering Ohm's law, we then apply it to get the final, lower current that is based on the reduced voltage Ef. We use the provided resistance in the question, that is 3 ohms.
Ef = (120 V) - (117 V) = 3 V
If = Ef/R = (3 V) / (5.0 Ω) = 0.6 A
The answer is C.) 36.9<span>°</span>