Yes, our friend is right, because there is no contradiction to the law of conservation of mass in the above equation. It just the mass of the product is equal to the mass of reactants.. and that is shown in the equation you have presented earlier
A . Thermal
Thermal Energy, or heat, is the internal energy in substance the vibration & movement of the atoms & molecules within substances. Geothermal energy is an example of thermal energy.
Answer:

Explanation:
As we know that when electron moved in electric field then work done by electric field must be equal to the change in kinetic energy of the electron
So here we have to find the work done by electric field on moving electron
So we have



now the distance moved by the electron is given as

so we have



now we have to convert it into keV units
so we have


Answer:
The magnitude of the change in momentum of the stone is 5.51kg*m/s.
Explanation:
the final kinetic energy = 1/2(0.15)v^2
1/2(0.15)v^2 = 70%*1/2(0.15)(20)^2
v^2 = 21/0.075
v^2 = 280
v = 16.73 m.s
if u is the initial speed and v is the final speed, then:
u = 20 m/s and v = - 16.73m/s
change in momentum = m(v-u)
= 0.15(- 16.73-20)
= -5.51 kg*m.s
Therefore, The magnitude of the change in momentum of the stone is 5.51kg*m/s.
I need a picture please befor i can answer