Constant Acceleration Kinematics – Linear and Projectile Motion
Displacement
- A rock is thrown straight upward off the edge of a balcony that is 5 m above the ground. The rock rises 10 m, then falls all the way down to the ground below the balcony. What is the rock's displacement?
- A child walks 5 m east, then 3 m north, then 1 m east. What is the magnitude of the child's displacement?
- An athlete runs exactly once around a circular track with a total length of 500 m. Find the runner's displacement for the race.
Speed and Velocity
- If the child from problem 2 completes his journey in 20 seconds, what is the magnitude of his average velocity?
- If the runner from problem 3 runs the lap in 1 minute 18 seconds, find his/her average speed and the magnitude of his/her average velocity.
- a.) Is it possible to move with constant speed but not constant velocity?
b.) Is it possible to move with constant velocity but not constant speed?
Acceleration
- A car drives in a straight line at a constant speed of 60 miles per hour for 5 seconds. Find its acceleration.
- A remote control car is driven along a straight track at 2 m/s. The child controlling the car then activates the toy's turbo mode so that, 3 seconds later, the car's speed is 3.2 m/s. Find its average acceleration.
- Shortly after, the remote control car in the previous example exits turbo mode, slowing from 3.2 m/s back to 2 m/s in 2 seconds. Find the car's average acceleration over this interval.
Uniform Acceleration with Equations of Motion
- A particle moves along the x-axis with an initial velocity of 4 m/s and constant acceleration. After 3 seconds, its velocity is 14 m/s. How far did it travel during this interval
- A car is initially moving at 10 m/s and accelerates at a constant rate of 2 m/s2for 4 seconds, in a straight line. How far did the car travel during this time?
- A rock is dropped from a cliff that is 80 m above the ground. If the rock hits the ground with a velocity of 40 m/s, what acceleration did it undergo?
Free Fall
- A rock is dropped 80 meters from a cliff. How long does it take to reach the ground?
- A ball is thrown straight up with an initial speed of 20 m/s. How high will the ball travel?
- One second after being thrown straight down, a rock is falling at 20 m/s. How fast will it be falling 2 seconds later?
- An object is thrown straight upward with an initial speed of 8 m/s and strikes the ground 3 seconds later. What height was the object thrown from?
Projectile Motion
- A tennis ball is thrown horizontally with an initial speed of 10 m/s. If it hits the ground after 4 seconds, how far did it drop before hitting the ground?
- A ball is thrown horizontally from a height of 100 m with an initial speed of 15 m/s. How far does it travel horizontally in the first 2 seconds?
- A javelin travels in a parabolic arc for 6 seconds before hitting the ground. Compare its horizontal velocity 1 second after being thrown to its horizontal velocity 4 seconds after being thrown.
- A circus performer is launched out of a cannon with a launch angle of 30oand an initial velocity of 40 m/s. How long after launch will it take for the performer to reach the top of his trajectory, and how high is this point?
- A cannonball is fired from the ground at a 30oangle with an initial speed of 60 m/s. If the cannonball lands back at the same height it was launched from:
a.) For how long will the cannonball be in the air?
b.) How far will it travel horizontally?
Kinematics w/ Graphs
- An object's position during a 10 second time interval is shown by the graph below:
a.) Determine the object's total distance traveled and displacement.
b.) What is the object's velocity at the following times:t= 1,t= 3, andt= 6.
c.) Determine the object's average velocity and average speed fromt= 0 tot= 10.
d.) What is the object's acceleration att= 5? - An object's velocity during a 10 second time interval is shown by the graph below:
a.) Determine the object's total distance traveled and displacement.
b.) Att= 0, the object's position isx= 2 m. Find the object's position att= 2,t= 4,t= 7, andt= 10.
c.) What is the object's acceleration at the following times:t= 1,t= 3, andt= 6.
d.) Sketch the corresponding acceleration vs. time graph fromt= 0 tot= 10.
- An object's position during a given time interval is shown by the graph below:
a.) At which of the marked points is the object's velocity the greatest? The least?
b.) Is the object's acceleration positive or negative between points A and B?