PHYSICS 1403, QUIZ 2, Chapter 3, February 6, 2006

PHYSICS 1403, QUIZ 2, Chapter 3, February 6, 2006
Partial credit will be liberal, provided that you show your work!
USE BACK IF NECESSARY! NOTE: You have about 15 minutes to do this quiz! So pace yourself!
Name: ______________________
1. (30 points) See figure. A person stands a horizontal distance d = 20 m from the
base of a building and throws a ball from the ground towards the building. It hits the
building at a height h = 15 m above the ground. At the point where it hits, its
vertical component of velocity vy = 0 (that is, at that point, its velocity is entirely in
the horizontal, x, direction!). The x & y components of it’s initial velocity, vx0 &
vy0, are unknown. In all calculations use g = 9.8 m/s2 for the acceleration due to gravity.
a. Compute the y component, vy0 of the initial velocity.
b. Compute the time t it takes the ball to hit the building.
c. Compute the x component, vx0 of the initial velocity.
d. Compute the length (magnitude) of the initial velocity vector v0 and the angle θ0 it makes
with the x-axis.
e. Compute the ball’s x and y components of velocity, vx and vy at a time t = 1.0 s after it is