Answer:
Not be changed
Option: D
<u>Explanation:</u>
The physical quantity which has both ‘magnitude and direction’ is called vector. These vectors are represented by a line and an arrow, <em>the line represent the magnitude and arrow represent the direction of the physical quantity</em>. The vectors are added and subtracted according to the direction of the vectors.
According to the vector law addition while adding vectors direction and length of the vector is not be changed.<em> If the length of the vector changed the magnitude is also changed while so, while adding vectors length must not be changed.
</em>
There is kinetic energy when it is sitting at the top, then as it goes towards the bottom, the kinetic energy is transformed into potential energy.
Answer:
1) Mass that needs to be converted at 100% efficiency is 0.3504 kg
2) Mass that needs to be converted at 30% efficiency is 1.168 kg
Explanation:
By the principle of mass energy equivalence we have

where,
'E' is the energy produced
'm' is the mass consumed
'c' is the velocity of light in free space
Now the energy produced by the reactor in 1 year equals

Thus the mass that is covertred at 100% efficiency is

Part 2)
At 30% efficiency the mass converted equals

Alkali Metals ......................................
Before solving this, you must know the definition of these units of measurement. Watt is a measurement of power which is the amount of energy per unit time in seconds. Energy, on the other hand, is expressed through the SI unit Joules. Thus, power is the amount of energy in Joules per second.
From here, you can use the dimensional analysis technique. Also, you should know that 1 kilowatt is equal to 1000 watts, and 24 hours is equal to 86,400 seconds. Then,
100 = Energy/86,400
Energy = 8,640,000 Joules