Answer:
4.5kgm/s
Explanation:
Change in momentum is expressed as
Change in momentum = m(v-u)
M is the mass
V is the final velocity
u is the initial velocity
Given
m=0.45kg
v = 30m/s
u = 20m/s
Substitute
Change in momentum = 0.45(30-20)
Change in momentum = 0.45×10
Change in momentum = 4.5kgm/s
Answer:
Explanation:
|F-->1| = E-->1 x charge on proton
= 300 x 1.6 x 10⁻¹⁹
Magnitude of electric force on proton
|F-->1| = 480 x 10⁻¹⁹ N .
Inside lithium nucleus , there are three protons so charge on it
= 3 x 1.6 x 10⁻¹⁹ = 4.8 x 10⁻¹⁹ C .
Magnitude of electric force on lithium nucleus
|F-->Li| = E-->1 x charge on lithium nucleus
= 300 x 4.8 x 10⁻¹⁹
= 1440 x 10⁻¹⁹ N .
Electron has same charge as that possessed by proton so charge on electron = 1.6 x 10⁻¹⁹ C
Magnitude of force on electron
|F-->1| = E-->1 x charge on electron
= 300 x 1.6 x 10⁻¹⁹
= 480 x 10⁻¹⁹ N .
Efficiency of heat engine is determined by the ratio of difference in temperature of cold from hot reservoir to the temperature of hot reservoir over temperature of hot reservoir.
Answer: Option A
<u>Explanation:</u>
Efficiency is defined as the output from the input. So it is the ratio of energy output to the energy input. In case of temperature, it is the change in temperature from hot reservoir to cold reservoir with the overall hot reservoir temperature.

Thus, option A is the most suitable as the heat will be transferred from high temperature to low temperature. So the hot reservoir will be releasing the energy. So the conversion of hot reservoir temperature to cool reservoir temperature is defined as the efficiency. Thus, option A is the most suitable.