Answer: vf1/vf2= 1/ sqrt(2)
Explanation :on the moon no drag force so we have only the force of gravity. aceleration is g(moon)= 1.62m/s2.the rest is basic kinematics
if the rock travels H to the bottom we can calculate velocity:
vo=0m/s (drops the rock) , yo=0
vf*vf= vo*vo+2g(y-yo)
when the rock is halfway y = H/2 so:
vf1*vf1=2*g*H/2 so vf1 = sqrt(gH)
when the rock reach the bottom y=H so:
vf2*vf2=2*g*H so vf2 = sqrt(2gH)
so vf1/vf2= 1/ sqrt(2)
good luck from colombia
True: Friction depends on the types of surfaces involved and how hard the surfaces push together.
Answer:


Explanation:
= Initial momentum of the pin = 13 kg m/s
= Initial momentum of the ball = 18 kg m/s
= Momentum of the ball after hit
= Angle ball makes with the horizontal after hitting the pin
= Angle the pin makes with the horizotal after getting hit by the ball
Momentum in the x direction

Momentum in the y direction


The pin's resultant velocity is 

The pin's resultant direction is
below the horizontal or to the right.
Answer: The level of CO2 has risen.
Explanation:
From the table shown, we can see that the quantity of CO₂ in the atmosphere has steadily risen since the year 1960 going from 317 CO₂PPM in that year to 390 CO₂PPM in 2010.
This is a cause for alarm because with so much carbon dioxide in the atmosphere, there will be an even greater greenhouse effect that will contribute to global warming.
I think it’s d but I’m not sure