Sophia Cali
Mr. Walsh
Period 6
2/22/11
1. In the absence of air resistance, why does the horizontal
component of velocity for a projectile remain constant,
and why does only the vertical component change?
There are no horizontal forces after the ball is let go. This means that there are no forces
to change the ball’s horizontal motion. Vertical motion is perpendicular to the ground. Gravity
pulls objects in projectile motion down with acceleration.
2. How does the downward component of the motion of a
Projectile compare to the motion of free fall?
With free fall the ball thrown would just fall to the ground. With the motion of a
downward projectile the balls velocity increases because gravity causes it to accelerate
downward.
3. at the instant a ball is thrown horizontally over a level range,
A ball held at the side of the first is released and drops to the
Ground. If air resistance can be neglected, which ball - the
one thrown or the one dropped from rest - strikes the
ground first?
The one dropped from rest will strike the ground first. This is because gravity pulls in projectile
motion down with acceleration, if air resistance is ignored. When the ball is thrown, there are no
horizontal forces acting on the ball.
4. Neglecting the effects of air resistance, explain why
after being thrown, the package remains directly
below the plane and the ball remains directly above
the truck.
Gravity hasn’t pulled it down yet. Also the horizontal velocity is constant.
Virtual Lab:
Initial Velocity
(m/s)
Range
(m)
10
30
45
60
80
10.19m
40.77m
91.74m
163.1m
254.84m
Maximum
Height
(m)
2.55m
10.19
22.93m
40.77m
63.71m
Final Velocity
Total Time
10 m/s
20m/s
30m/s
40m/s
50m/s
1.44s
2.88s
4.32s
5.77s
7.21s