P = m*v
7.5 = m*15
m = 7.5/15 = 0.5 kg
F - False.
The law of conservation of momentum states that the total momentum is conserved.
Wildlife researcher starts from a and then reaches b, he turns towards north 40 degree to move towards c.
Total displacement is ac
Total horizontal displacement = 4+4 cos40 =7.06 km
Total vertical displacement = 4 sin40 =2.57 km
Total displacement 
= 7.51 km
Answer: The correct answer is "No".
Explanation:
Gravity: It is the force which causes object to fall on the earth. It is the force which attracts bodies towards each other.
Potential difference: It is defined as the potential acting between the two points. The work done in moving the unit positive charge from one location to the another location.
The potential difference in battery is caused by the electrodes. There are two terminals in battery: Negative terminal which is at lower potential and Positive terminal which is at higher potential. It forces the electrons to flow in the circuit which constitutes the current.
The gravity and the potential difference have no relation between them.
Therefore, gravity have no effect on the potential difference of a battery.
E) Protons, neutrons, and electrons
