Answer:
option D
Explanation:
given,
mass of the rifle,M = 2 Kg
mass of the bullet , m = 0.01 Kg
speed of the bullet, v = 200 m/s
recoil velocity ,v'= ?
initial velocity of bullet and rifle is zero.
using conservation of energy
Mu + m u' = M v'+ m v
0 + 0 = 2 x v' + 0.01 x 200
2 v' = -2
v' = -1 m/s
negative sign represent the velocity of rifle is in opposite direction of bullet.
hence, the correct answer is option D
If a hot air balloon has shown rising above the top of a hill, the top of the hill is considered as a reference point.
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Reference Point:</h2>
It is a point that is used to standardize a experiment. The reference point is a constant point.
In the given problem:
- The hot air balloon is rising above the top of the hill. Here, the hill is a standard point that has a fixed (constant) height.
- Some other reference points are the top of the Eifel Tower or a famous shop which a person use to denote a certain distance.
Therefore, "If a hot air balloon has shown rising above the top of a hill" the top of the hill is considered as a reference point.
Learn more about Reference Point:
brainly.com/question/1674904
The correct answer is 223 days.
The relationship between the duration of revolution and the separation between the sun is shown by Kepler's third law. Using the notions of circular motion and the gravitational and centripetal forces, we may obtain this equation.
According to Kepler's third rule, the semi-major axis of an orbit is linked to the orbital period of a planet around the sun as follows:
p² = a³
where an is the semi-major axis/distance to the star and p is the orbital period in years.
It is said that a = 0.72 AU for Venus.
P= √(0.72 AU)^3 = 0.61 years.
365 days in a year = 222.9 ≈ 223 days.
To learn more about Kepler's third rule refer the link:
brainly.com/question/1608361
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