I would use a resistor rated for 1 W or more. Not less.
Answer:
the kinetic energy lost due to friction is 22.5 J
Explanation:
Given;
mass of the block, m = 0.2 kg
initial velocity of the block, u = 25 m/s
final velocity of the block, v = 20 m/s
The kinetic energy lost due to friction is calculated as;

Therefore, the kinetic energy lost due to friction is 22.5 J
To calculate the velocity of the sound wave, we use this formula:
V = 331 + [0.6*T],
Where V is the velocity and T represents temperature.
When the temperature is 36 degree Celsius, we have
V = 331 + [0.6 * 36]
V = 331 + 21.6 = 352.6
Therefore, V = 352.6 m/s.
Answer A: When their separation increases.
Hope this helps! :D
Answer: c
Explanation: because if it increases then it gets hotter
if it decreases then its getting colder.