The change in momentum is 240 kgm/s
<u>Explanation:</u>
Given:
Force, F = 120N
Time, dt = 2 sec
Change in momentum, dP = ?
We know,

On substituting the value we get:

Therefore, change in momentum is 240 kgm/s
C. 340
Frequency is the number of wavelengths per second and since the length is 0.5 you multiply 0.5*686 and get 343.
the question not allowing for one position thus the answer is c
Answer:
The pressure of the solid on the surface depends on the area of contact. The area of contact between the two surfaces. The greater the force or the smaller the area the greater the pressure.
(credits to the rightful owner for these answers :)
Answer:
Star, hydrogen and energy
Explanation:
A star is a large ball of gas that generates its own energy by fusing hydrogen atoms to make helium. It is held together by its own gravity. This process emits a tremendous amount of energy, and some of the energy is in the form of light.
The energy released from the collapse of the gas into a protostar causes the center of the protostar to become extremely hot. When the core is hot enough, nuclear fusion commences. Fusion is the process where two hydrogen atoms combine to form a helium atom, releasing energy.