<span>D. density is your answer</span>
Answer:
-The battery-the power source
-Closed conducting loop
Explanation:
-To produce an electric current, the following requirements must be met:
-A battery-This is the energy source than will do work on the charge thus moving from a low energy location to high energy location.
-Closed Conducting Loop-The loop is usually made of copper wires due to their high electric conductivity.
Answer:
thermal energy
Explanation:
heat transfers into it causing it to physically change
Answer:
The block's mass should be 
Explanation:
Given:
Cart with mass 
From the conservation of energy before mass is added,

Where
amplitude of spring mass system,
spring constant

Now new mass
is added to the system,


Here, given in question frequency is reduced to half so we can write,

Where
frequency of system before mass is added,
frequency of system after mass is added.




Therefore, the block's mass should be 