Regents Physics Midterm Study Guide
TWO DIMENSIONAL MOTION
1. Horizontal velocity remains constant
2. Time is the same for both vertical and horizontal motion
3. The angles complement to each other goes the same distance
4. If the question asks what the initial horizontal velocity component was, you only need to look at the
horizontal reach and the time, and use d = v t or v = d/t. (a = 0 horizontally).
5. A graph of the horizontal motion of a projectile should show no acceleration. If it is a distance vs time graph
then it should be a straight line, and if it is a speed vs time graph then it should be a constant flat line.
6. Make separate lists for horizontal(x) and vertical(y) components, since pretty much all of the variables are
different! For example, horizantal velocity remains constant throughout the problem!
7. Look out for key words (i.e. horizontal)--they'll help you understand what the question wants you to find/do.
8. Why does a projectile following the path of a parabola hit the ground at the same time as a free-falling
object? The initial vertical velocity for both objects is the same--"0" and both objects undergo the same
acceleration due to gravity. Therefore, they fall at the same rate and hit the ground at the same time.
9. In order to calculate the horizontal distance or the range the following formula can be used for a projectile at
an angle, (however this is not recommended, since it is not in the reference tables):
Range i sin( 2 )
10. or if given the time, use vix = (cosine of the given angle)*(given velocity) and R=vixt, where vix=initial
velocity of horizontal component, t=time. This leads to Range v x t (v cos )(2 )
11. The longest time in air corresponds to greater initial angle.
12. The larger the initial angle, the greater the maximum height.
13. The lower the initial angle, the lower the maximum height.