The mily way is an example of D. Barred spiral galaxy
Answer:
Explanation:
We shall apply law of conservation of momentum .
m₁ v₁ = m₂ v₂
m₁ = 80 kg
v₁ = ?
m₂ = .43 kg
v₂ = 15 m /s
80 v₁ = .43 x 15
v₁ = .43 x 15 / 80
= .08 m /s
8 cm /s
option A is correct.
Law of conservation of momentum is applied only where no external force acts . Here during the period when ball was thrown , apart from internal force , external force like gravitational force was also acting but we still applied this law because the time duration of action of throw was very small
so we neglected the effect of external force . So it was just an approximation.
Answer:
2.73 km/s
Explanation:
The escape velocity of an object in the gravitational field of the moon is (on the surface of the planet)
where
is the gravitational constant
is the mass of the Moon
is the radius of the Moon
As we can see, the escape velocity does not depend on the mass of the lunar module.
Substituting the numbers into the formula, we find
B is the right answer. Multiply numbers you get the answer
