1. A person kicks a rock off a cliff horizontally with a speed of 20 m/s. It takes 7.0 seconds to hit the
ground, find:
a. height of the cliff
b. final vertical velocity
C. range
D.speed and angle of impact

This problem involved half projectile.

initial velocity, vo = 20 m/s

time of flight, t = 7 s

(a) Simply use the formula to get the height, h:

h = vo*t - (1/2)gt^2

(b) To get the final vertical velocity or terminal velocity (vf), use the formula:

(vf)^2 - (vo)^2 = 2gh

(c) Use the formula find the horizontal distance traveled, R:

R = vo * cos(θ) * t

But since the angle involved with respect to horizontal is zero, and cos(0) = 1, we have

R = vo * t

Hope this helps~ `u`

Jai

Which sentence accurately uses the homophones “they’re,” “there,” or “their”?

Many of the students left there backpacks on the bus.
They’re going to come home as soon as the movie is over.
I think I left the bags of groceries on the floor over their.
These dogs bark at everyone, but there not dangerous at all.

4. While cleaning your bedroom, you move your mattress to vacuum underneath your bed. You use a force of 48 N to move the mattress 1.5 meters out of the way. How much work was done?