From the top of a  90 m high cliff, a student  throws a rock vertically downwards with a velocity of 7 m/s. How long will it take for this rock to reach the bottom of the cliff? A.) 4.8 s B.) 5.1 s C.) 2.6 s D.) 3.6 s

the second part of it  e) Determine the average speed of the object from zero to the moment when the object changes direction along the x-axis.

At a stop light, a truck traveling at 10.5 m/s passes a car as it starts from rest. The truck travels at constant velocity and the car accelerates at 3 m/s2. How much time does the car take to catch up to the truck? A) 3 s B) 7 s C) 12 s D) 20 s F) 25 s

1. What direction is the velocity from t=0s to t=3s? a)0 b)- c)Cannot be determined d)+   2. At which time is the object changing direction? a)3s b)The object is never changing direction during the time interval shown. c)5s d)6s e)7s   3. What is the sign of acceleration (or Δv ) from t=3s to t<5s? a)0 b)- c)Cannot be determined d)+   4) What is the sign of acceleration (or Δv ) at t=5s? a)0 b)- c)Cannot be determined d)+

A little girl accidentally drops a 62 kg object from her balcony. This balcony has a height of 493 feet. 1.)How long will it take the object to hit the pavement? 2.)Sketch a graph of the displacement of the object as a function of time.

A goalie completes a goal kick with the ball on the ground. The ball has a vertical velocity of 35 m/s and a horizontal velocity of 20 m/s when it leaves the goalie's foot. How long is the soccer ball in the air? Ignore air resistance. A.) 3.57 s B.) 2.04 s C.) 7.14 s

During which of the following time intervals is the object moving in the negative direction? A. 0-4 seconds B. 4 to 7 seconds C. 7 to 10 seconds  D. All of the intervals listed above E. None of the intervals listed

Which of the following descriptions corresponds to a ball tossed vertically upward? Air resistance can be neglected. a. The velocity decreases linearly from v_0 to v_f, with v_0>0 and v_f<0. b. The velocity increases linearly from zero to v_f. c. The position first increases linearly and then decreases linearly as a function of time. d. The acceleration decreases linearly from g to zero.

1. A ball is thrown vertically upward from the ground with a speed of 36.0 m/s. Suppose the acceleration of gravity were only 2.00 m/s² instead of 9.80 m/s² a) At what time after being thrown does the ball have a velocity of 12.0 m/s upward? b) At what time does it have a velocity of 12.0 m/s downward? c) When is the velocity of the ball zero? d) When is the displacement of the ball zero? e) What are the magnitude and direction of the acceleration while the ball is moving upward? f) What are the magnitude and direction of the acceleration while the ball is moving downward? g) What are the magnitude and direction of the acceleration when it is at the highest point?

Use the position function ?(?) = −4.9t2 + v0 + s0 for free-falling objects.  A rock is dropped from the edge of a cliff that is 176.4 meters above the water A. Determine the position function for the rock B. Find the velocity function for the rock. C. Find the velocity when t = 2 seconds. D. Find the time required for the rock to reach the surface of the water E. Find the velocity of the rock at impact with the water.