1. An object's motion is described by the following graph of position vs. time: a. What is the object doing between 2 s and 4 s? What is its velocity during 90 that interval? 72 54 b. What is the object doing between 6 s and 7 s? What is its velocity during 36 18 that interval? 1. 2 4 5. 8 10 Time (s) C. During which time interval(s) is the object at rest? During which time interval(s) is it moving at a constant velocity? During which time interval(s) is it accelerating?

PW-3 An elevator motor is capable of lifting a 2,500kg elevator 50.0m with a constant speed in 12.0 seconds. a) Apply Fet ma to find the force needed to lift the elevator. b) Find the power of the elevator motor in watts and in horsepower. (1H.P.-750W) c) If the power of the elevator motor is 200H.P., find the constant speed at which the 2,500kg elevator can be raised. d) If the power of the elevator motor is 200H.P., find the constant speed at which the elevator can be raised if the elevator and its contents have a mass of 4,000kg

Hicham El Guerrouj of Morocco holds the world record in the 1500 m running race. He ran the final 400 m in a time of 51.9 s. What was his average speed in mph over the last 400 m?A. 14.2 mph                      B. 15.5 mphC. 17.2 mph                      D. 23.9 mph

7. A feather is dropped on the moon from a height of 1.40 meters. The acceleration of gravity on the moon is 1.67 m/s?. Determine the time for the feather to fall to the surface of the moon. a. 2.29 s b. 1.29 s. c. 1.29 m d. 0.29 s. a C d

The position graph shows a dog slowly sneaking up on a squirrel, then putting on a burst of speed.a. For how many seconds does the dog move at the slower speed?b. Draw the dog’s velocity-versus-time graph. Include a numerical scale on both axes.

A ball is thrown straight up. What is the velocity and  acceleration of the ball at the higest point (peak)?   A. velocity = 0m/s and acceration = 9.8 m/s2 down.   B. velocity = 0 m/s  amd acceleration = 0 m/s2   C. velocity = 0 m/s and acceleration = 9.8 m/s2 up   D. velocity = 9.8 m/s up and acceleration = 0 m/s2

An object moves in one dimension, and its velocity versus time is shown in the graph. Express your answers in m/s2. A. What is the average acceleration between the times 0 s and 20 s?  B. What is the average acceleration between the times 20 s and 50 s?  C. What is the average acceleration between the times 50 s and 70 s?  D. What is the average acceleration between the times 0 s and 100 s?

1. The acceleration of a car is given by a(t) = A – Bt + Ct² , where A = 1.0 m/s², B = 0.5 m/s³, C = 2.0 m/s“. The car is at rest at the origin at time t= 0. Find its position and velocity as a function of time. b. Sketch its position, velocity, and acceleration. a.

1. Refer to the velocity-time graph of a jogger. The positive direction is away from the jogger's home. Rank the four distances for the time intervals, A, B, C, D in decreasing order. Explain your answer. 15 10 C 40 50 30 20 Time (s) 0. 10 20 (s/w) pe 25

a. Draw the velocity graphs of Vy and Vx as a function of time. b.Draw x and y component of the position as a function of time. c. how long does it take for the rock to hit the ground? d. what is distance X where the rock hits the ground from the base of the vertical cliff?