Answer:
When the velocity doesn't change its direction
Explanation:
Since velocity vector has 2 components: direction and magnitude, and speed is the velocity's magnitude. So if the velocity doesn't change its direction, we essentially use its magnitude, aka speed, to calculate the rate of change for acceleration.
Answer:
M. Magnetism is a property of individual atoms.
Explanation:
when a magnet is broken into pieces the new pieces behave like the original magnet this observation shows that magnetism is the property of individual atoms.
Answer:
The capacitance of the capacitor is 
Explanation:
To solve this exercise it is necessary to apply the concepts related to Power and energy stored in a capacitor.
By definition we know that power is represented as

Where,
E= Energy
t = time
Solving to find the Energy we have,

Our values are:


Then,


With the energy found we can know calculate the Capacitance in a capacitor through the energy for capacitor equation, that is

Solving for C=



Therefore the capacitance of the capacitor is 