Knowns
The acceleration in the y direction of a launched object. (Include direction and units.)
What is -10 m/s2 ?
This is what the theta (θ) symbol stands for.
What is the symbol for an angle?
What are viy=0 m/s, ax = 0 m/s2, and ay = -10 m/s2?
What is the vertical initial velocity?
This common student error occurs when a student fills in the following variables for a horizontally launched object.
x = 15m, vix = 25 m/s, viy= 0 m/s, ax= -10 m/s2, ay=-10 m/s2
What is using the y acceleration for the x direction?
What is the cosine?
The initial horizontal velocity for a ball thrown horizontally off a cliff is 40 m/s. The ball stays in the air for 3 seconds. How far from the base of the cliff does it land?
What is 120 m?
This is the initial velocity in the y direction when the overall initial velocity is 25 m/s at an angle of 14 degrees.
What is 6 m/s?
This error involves a student using a velocity of 15 m/s at an angle of 35 degrees to solve for the x component. (35cos(15) = vix)
What is switching the angle and the hypotenuse?
This quantity is the same for both the horizontal and vertical directions.
What is the time?
What is the initial velocity in the vertical direction?
The initial horizontal velocity for a ball thrown horizontally off a cliff is 75 m/s. If the ball is in the air for 7 seconds. How far down does the ball drop?
What is 245 m?
This is the final vertical velocity when we are finding the max height of an object launched at an angle. (Include units)
What is 0 m/s?
This error happens when a student is working a horizontal projectile motion problem and their known variables look like the following.
x= 14 m, vix = 1.25 m/s, viy = 1.25 m/s, ax= 0 m/s2 and ay=-10 m/s2
What is using the wrong viy or not using 0 as the viy?
The equation used when you have displacement, time, initial velocity and acceleration.
What is Δx = vi(Δt) + 1/2aΔt2 ?
This is the opposite side of a triangle with an angle of 25 degrees and a hypotenuse of 15 m/s. (Must include units.)
What is 6.3 m/s?
If a bird flying horizontally at 1.5 m/s drops a worm 4.5 meters above the ground, this is the worm's vertical velocity when it hits the ground.
What is 9.5 m/s?
A basketball is thrown at 3.4 m/s at an angle of 12.5 degrees. If the ball is in the air for 2.8 seconds, this is the ball's final vertical velocity.
What is -27 m/s?
This error occurred when students were using a formula to calculate the horizontal displacement shown below.
Δx=vi(Δt) + 1/2aΔt
What is forgetting to square the Δt?
This is the strategy used to find the initial velocity in the x direction when given an angle. (Must be specific.)
What is the trig function cosine?
This is the vertical component of the velocity when an object is launched at 26 m/s at an angle of 17 degrees. (Must include units.)
What is 25 m/s?
The initial horizontal velocity for a cannon ball is 28 m/s. If the cannon ball falls 2.5 meters, how far away does it land?
What is 19.8 m/s?
A rock is kicked off a building with an initial velocity of 40 m/s at an angle of 30 degrees. If the rock is in the air for 9 seconds, this is how far the rock falls.
What is 225 meters?
This error occurred when the student was calculating the Δt for a rock falling to the ground.
10 m = 1/2(-10)(Δt)2
What is forgetting to make the Δy a negative?