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 &
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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
thrown.
d
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