Physics 12
Projectile Motion and Springs
Name _________________
Please answer all questions in the space provided. The point value for each question is
located at the end of the question.
(1) A ball is thrown with a velocity of 10.0 m/s at an angle of 30.0° above the
horizontal. What is the horizontal and vertical component of the velocity? (4
points)
(2) A ball thrown horizontally at 21.0 m/s from the roof of a building lands 24.0 m
from the base of the building. How high is the building? (6 points)
(3) An arrow is fired with a velocity of 90.0 m/s at an angle of 50.0° above the
horizontal. (a) What is the arrow’s maximum height above its release point and
(b) How far does the arrow travel horizontally before returning to its original
height? (8 points)
(4) A 40.0 N force causes a spring to be stretched 0.200 m from its rest position.
What is the spring constant of the spring? (2 points)
(5) What is the change in elastic potential energy as the spring in question 4 is
stretched from 0.200 m from the rest position to 0.400 m from the rest position?
(5 points)
(6) A 2.00 kg mass is pushed against a spring of spring constant 150. N/m
compressing the spring 0.200 m from its rest position and held in place such that
the system is at rest. The system is then released so that the mass is pushed by
the spring as the spring is uncompressed. What is the speed of the mass as the
spring reaches its rest position? Assume there is no friction. (5 points)
(7) An Olympic long jumper is capable of jumping 8.00 m. Assuming his horizontal
speed is 9.00 m/s as he leaves the ground, how long is he in the air and how high
does he go? (8 points)
(8) An elevator cable breaks when a 750. kg elevator is 25.0 m above a huge spring
(k = 40000. N/m) which is located at the bottom of the elevator shaft. Calculate (a)
the work done by gravity on the elevator before it hits the spring. (b) the speed of the
elevator just before striking the spring. (c) the amount the spring compresses
(remembering that as the spring compresses, the elevator is still losing gravitational
potential energy). (12 points)