Answer:
(d) a net external force must be acting on the system
Explanation:
Momentum is given as the product of mass and velocity.
P = MV
According to Newton's second law of motion, " Force applied to a body (system) is directly proportional to the rate of change of momentum of the body (system) which takes place in the direction of the applied force (external force).
F ∝ΔMV
Therefore, If the total momentum of a system is changing, a net external force must be acting on the system.
(d) a net external force must be acting on the system
Answer:
The amount of energy is directly proportional to the photon's electromagnetic frequency and thus, equivalently, is inversely proportional to the wavelength. The higher the photon's frequency, the higher its energy.
i hope this helps.
Explanation:
Answer:
v = 1.6 m/s
Explanation:
Given that,
Distance, d = 72 m
Time taken, t = 45 s
We need to find their average velocity. Average velocity of an object is given by total distance divided by total time taken.

So, their average velocity is 1.6 m/s.
Answer:
Momentum change of the rock = 3835 kgm/s
Chane in earth's velocity = 6.4 x 10⁻²² m/s
Explanation:
m = 50.0 kg, M = 6.0 x 10²⁴ kg
d = 300.0 m
final velocity of rock = v, v² = 2gd = 2 * 9.81 * 300, so v = 76.7 m/s
Momentum change of the rock = mv = 50.0 * 76.7 = 3835 kgm/s
Inital momentum of the rock+earth system = 0
final momentum = 0 (momentum conservation)
momentum of rock and momentum of earth are same magnitude and opposite directions.
mv - MV = 0
Chane in earth's velocity = mv/M = 3835/(6.0 x 10²⁴) = 6.4 x 10⁻²² m/s
amswer
25+(0.58*5.2) 25+3.016 28.016m/s^2