Worksheet 2 - Modeling Physics

Name
Particle Models in Two Dimensions Worksheet 2:
Horizonally Launched Projectiles
1. Given the following situation of a marble in motion on a rail with negligible F friction :
a. Sketch a motion map showing the motion of the marble after it leaves the rail, using the
grid to help you carefully locate the marble’s positions. Show both horizontal and vertical
velocity vectors on each dot.
h = 1.5 m
b. Sketch and label force diagrams for the marble both when it is on the rail and off the rail.
Describe the horizontal and vertical motion of the ball in each case.
c. Once the ball leaves the table, calculate how long it will take for the ball to hit the floor.
d. In the time you have calculated in part c, how far will the ball travel horizontally before
hitting the floor
e. Suppose the table was doubled in height to 3.0 m. Determine the horizontal range of the
marble as it falls to the floor. What effect does doubling the height have on range of the
marble What other factors affect the range of the sphere
©Modeling Instruction 2010 1 U6 2D Motion - ws 2 v3.0

2. A student finds that it takes 0.20s for a ball to pass through photogates placed 30 cm apart on a
level ramp. The end of the ramp is 92 cm above the floor. Where could a coin be placed so that the
ball directly strikes the coin on impact with the ground
3. Suppose now that the same ball, released from the same ramp (92 cm high) struck a coin on the
floor placed 25 cm from the end of the ramp.
a. What was the ball's horizontal velocity
b. How long did it take for the ball to pass through the photogates
©Modeling Instruction 2010 2 U6 2D Motion - ws 2 v3.0

In all the problems below, draw a diagram to represent the situation. Identify the knowns
and unknowns and label clearly.
4. The movie "The Gods Must Be Crazy" begins with a pilot dropping a bottle out of an airplane. A
surprised native below, who thinks it is a message from the gods, recovers it. If the plane from
which the bottle was dropped was flying at a height of 500m, and the bottle lands 400m horizontally
from the initial dropping point, how fast was the plane flying when the bottle was released
5. Suppose that an airplane flying 60 m/s, at a height of 300m, dropped a sack of flour. How far
from the point of release would the sack have traveled when it struck the ground Where will the
plane be in relation to the sack when the sack hits the ground Illustrate your answer carefully using
the grid provided.
6. In many locations, old abandoned stone quarries have become filled with water once excavating
has been completed. While standing on a quarry wall, a boy tosses a piece of granite into the water
below. If he throws the rock horizontally with a velocity of 3.0 m/s, and it strikes the water 4.5 m
away, how high above the water is the wall
©Modeling Instruction 2010 3 U6 2D Motion - ws 2 v3.0

7. Tad drops a cherry pit out the car window 1.0 m above the ground while traveling down the road
at 18 m/s. How far, horizontally, from the initial dropping point will the pit hit the ground If the car
continues to travel at the same speed, where will the car be in relation to the pit when it lands
8. A kickoff sends a football with an initial velocity of 25 m/s at an angle of 50 degrees above
horizontal.
a. Find the x and y-components of the velocity
b. Find the time the ball is in the air
c. Find the horizontal distance the ball travels before hitting the ground.
d. Find the maximum height of the ball.
©Modeling Instruction 2010 4 U6 2D Motion - ws 2 v3.0