Answer one of these two questions in the space below: 1) you and a friend have built a go-cart! your friend pushes you on a level parking lot with a constant force for five seconds, resulting in a final speed of a respectable 15 m/s. you then coast 80 meters to a stop. determine the accelerations for both parts of the trip (assumed constant). also determine the total time of travel and the total distance traveled. 2) a machine launches a tennis ball with an initial vertical velocity of 9.0 m/s and an initial horizontal velocity of 4.5 m/s. determine the magnitude and direction of the initial velocity vector. determine the range of the tennis ball (the horizontal distance the ball would travel if it was launched on a level surface) and the maximum height. finally, determine the position of the ball (x. y) at 1.25 seconds.

A23 kg log of wood begins from rest, 300 m up a sluice (a water track used to transport logs, think of it as an inclined plane with negligible friction) inclined at 20° to the horizontal. after it reaches the flat waterway at the bottom it collides elastically with a 100 kg block of wood initially at rest near the base of the incline. (a) how long does it take the 23 kg log to travel down the incline? (b) what is the speed of the 23 kg log at the bottom of the incline? (c) what are the velocities of both blocks of wood after the collision? (d) what is the total kinetic energy before the collision? (e) what is the kinetic energy of the 23 kg log after the collision? (f) what is the kinetic energy of the 100 kg block of wood after the collision? (g) what is the total kinetic energy after the collision? (h) compare the total initial and total final kinetic energies. is this consistent with what you would expect for elastic collisions? explain!

The x-coordinate of a particle in curvilinear motion is given by x = 3.1t3 - 4.9t where x is in feet and t is in seconds. the y-component of acceleration in feet per second squared is given by ay = 2.3t. if the particle has y-components y = 0 and vy = 5.0 ft/sec when t = 0, find the magnitudes of the velocity v and acceleration a when t = 1.8 sec. sketch the path for the first 1.8 seconds of motion, and show the velocity and acceleration vectors for t = 1.8 sec. answers: v = ft/sec a = ft/sec2

In which of the following cases is work being done on an object? question 2 options: pushing against a locked door carrying a box down a corridor pulling a trailer up a hill suspending a heavy weight with a strong chain