The period of a pendulum is given by

where L is the pendulum length and g is the gravitational acceleration.
We can write down the ratio between the period of the pendulum on the Moon and on Earth by using this formula, and we find:

where the labels m and e refer to "Moon" and "Earth".
Since the gravitational acceleration on Earth is

while on the Moon is

, the ratio between the period on the Moon and on Earth is
Let say the two train cars are of masses
and 
now if the speed of two cars are
and 
then we can say that the momentum of two cars before they collide is given by

here two cars are moving in opposite direction so we can say that the net momentum is subtraction of two cars momentum.
Now since in these two car motion there is no external force on them while they collide
So the momentum of two cars are always conserved.
hence we can say that the final momentum of two cars will be same after collision as it is before collision

Answer:
Geology is the study of planet Earth, including its composition and structure. Geologists are scientists who study Earth and the processes that shape Earth over time. Geologists study two types of forces that change Earth's surface.
Explanation:
please mark me brainliest
Answer:
I think the answer is b am sorry if it is wrong
Explanation:
Answer:

Explanation:
We know that the tangent function relates the angle of the right triangle that forms the hot air balloon rising:

Differentiating (1) with respect to time, we get:

since x is a constant value. Replacing:
