What is the speed of the rock just before it hits the

Question

1. What are the kinematic equations for 1D motion?

2. A small rock is thrown vertically upward with a speed of 18.0 m/s from the edge of the roof of a 30.0-m-tall building. The rock doesn't hit the building on its way back down and lands in the street below. Air resistance can be neglected.

(a) What is the speed of the rock just before it hits the street?

(b) How much time elapses from when the rock is thrown until it hits the street?

3. The position of the front bumper of a test car under microprocessor control is given by x(t) = 2.17 m + (4.80 m/s²)t² - (0.100 m/s⁶)t⁶. (a) Find its position and acceleration at the instants when the car has zero velocity. (b) Draw x-t, Vx-t, and a_xt graphs for the motion of the bumper between t = 0 and t = 2.00 s.

4. A physics professor leaves her house and walks along the sidewalk toward campus. After 5 min it starts to rain, and she re­turns home. Her distance from her house as a function of time is shown in Fig. 1.

At which of the labeled points is her velocity

(a) zero?
(b) Constant and positive?
(c) constant and negative?
(d) Increasing in magnitude?
(e) Decreasing in magnitude?