A stone falls from rest from the top of a cliff. A second stone is thrown downward from the same height 3.4 s later with an initial speed of 66.64 m/s. They hit the ground at the same time. How long does it take the first stone to hit the ground?

A stone falls from rest from the top of a cliff. A second stone is thrown downward from the same height 3.4 s later with an initial speed of 66.64 m/s. They hit the ground at the same time. How long does it take the first stone to hit the ground? The acceleration of gravity is 9.8 m/s2 . Answer in units of s
In your frame, a certain galaxy is moving at a high speed in the x-direction. Relative to the galaxy, a certain comet in the galaxy is also moving at a high speed in the x-direction. Let a be the galaxy’s speed with respect to you, b be the comet’s speed with respect to the galaxy, and c be the comet’s speed with respect to you. Then
Select one:
a. a + b > c
b. a + b < c c. a + b = c d. a 2 + b 2 = c 2 Jamal is skating on a sidewalk. His initial velocity is 0.0 m/s ; 35 seconds later hid velocity is 5.0 m/s. What is his acceleration