Answer:
A kilowatt (kW) is a unit of power.
Explanation:
The power of an object is given by :
Here,
E is the energy required
t is time
The SI unit of power is Watts and the SI unit of energy is Joule. the commercial unit of energy is kilowatt per hour.
Option (1) : A kilojoule (kJ) is a unit of power is incorrect.
Option (2) : A gigawatt (GW) is a unit of energy is incorrect.
Option (3) : A watt (W) is a unit of energy is incorrect.
Option (4) : A kilowatt x hour per year (kWh/yr) is a unit of energy is incorrect.
Option (4) : A kilowatt (kW) is a unit of power is correct.
Hence, the correct option is (d).
Answer:
the answers is 1.
Explanation:
this is because heat always travel's from the warmest object to the coldest. His hands thermal energy is transferred to the ice making the ice round to the same temperature of his hand. This can also be an example of equalibrum.
The work done by the friction force to stop the player is equal to his loss of kinetic energy:
The work done by the friction force is the magnitude of the force
times the distance covered by the player, d:
The loss in kinetic energy is simply equal to the initial kinetic energy of the player, since the final kinetic energy is zero (the player comes to rest):
Substituting into the first equation, we get:
from which we find d, the distance covered by the player:
Answer:
From spectral lines astronomers can determine not only the element, but the temperature and density of that element in the star.
