Math 1210-007
Practice Problems
Fall 2010
Practice Problems - 11/9/10
1.
You shoot bullet from a gun at a 30° angle and the bullet leaves the gun with a velocity of
1200 ft./s. Assume that you held the gun over your head when you pulled the trigger so
that the gun is 6ft. above the ground when the bullet leaves it. Recall that gravity causes
all objects to accelerate downward with at a rate of 32ft./s2.
(a)
Write an equation for x(t) that describes the bullet's horizontal motion over time.
Answer:
(b)
Write an equation for y(t) that describes the bullet's vertical motion over time.
Answer:
(c)
What is the maximum height reached by the bullet?
Answer = 5,631 ft
(d)
How long does it take for the bullet to hit the ground?
Answer = 37.51 s
(e)
How far away from the gun does the bullet land?
Answer = 38,981.53 ft
(f)
Suppose instead that the gun was shot at the same angle but started at ground
level. How far away would the bullet land in this scenario?
Answer = 38,971.14 ft
2.
A 5kg object experiences a net force of 30 N at an angle of 60°. Assume the object is
initially at rest and at ground level (Do not include the force of gravity).
(a)
Write an equation for x(t) that describes the object's horizontal motion over time.
Answer:
(b)
Write an equation for y(t) that describes the object's vertical motion over time.
Answer:
(c)
How far has the object moved in the horizontal and vertical directions after 6
seconds?
Answer:
(d)
,
m
After 6 seconds, what is the objects overall distance from where it started?
(HINT: Pythagorean Theorem)
Answer =