Homework #2
Instructions: Complete 5 of the following 7 questions. Each correct answer is worth 10 points,
and submitting this homework automatically scores you 50% of the points. Each correct answer
beyond the 5 required will score you +1pt of extra credit.
1. If each marking on the graph below represents 1 ft, what is the position of the orange
ball? Express your answer in the format “s = _____ft x”
Your Answer: 4ft
2. Two graphs are given below. The first represents the position of an object at time t =
0.00s, and the second represents its position at t = 5.00s. If each marking represents
1.00 m, what is the velocity of the object?
Your Answer: 0.2m/s
3. You’re driving down the thruway and you see a sign 50 m in front of you. 2 seconds later,
the sign is right next to your car (0 m in front of you). What is the velocity of your car?
Your Answer: - 25m/s
4. It takes a car 5.00 seconds to move from si = 11.0 m to sf = 1.00 m. What is the velocity
of the car? (Note: Your answer should turn out negative.)
Your Answer: -2m/s
5. Your friend gets in their car to go to work. At first, their velocity is v i = 0.000 m/s, but after
7.00 seconds their velocity is vf = 27.0 m/s. What is the acceleration of their car? (Use
significant digits in your final answer, and don’t forget your units.)
Your Answer: 4m/s
6. An object starts off with an initial velocity of vi = 90.0 ft/min at an initial time of ti = 5.00
min. If its final velocity is vf = 30.0 ft/min at a time of tf = 8.00 min, what is the
acceleration of the object? Your answer should have units of ft/min2.
Your Answer: -20ft/min2
7. You’re on a mission to travel to another planet when you find yourself caught in the
gravity of a black hole! In order to escape, you need to accelerate away from it at a rate
of 521 m/s2. If at first your velocity is 56.0 m/s and, 3.00 seconds later, your velocity is
423 m/s, what is your acceleration? Are you accelerating fast enough to escape the
black hole?
Your Answer: 399m/s .No i’m not accelerating fast enough