0. (a) The y-verions of the free fall equations are written
below with one exception. What is the equation for the acceleration, ay?
(b) What is the x-acceleration of an object in free fall?
(c) Write the equivalent equations for the x motion of an object in free fall.
| 1. HRW 6, Q 4.7 In the figure below, a cream tangerine
is thrown up past windows A, B, and C, which are identical in size and regularly
spaced vertically. Rank the times needed to pass the windows starting with
the window having the largest time. (Answers might be A=C>B for example.)
Does the regular spacing matter? The tangerine now passes by windows D,
E, F which are identical to each other and regularly spaced. Rank the times
needed to pass the windows starting with the window having the largest time.
Does the regular spacing matter? What about ordering them by distance that the tangerine travels as it passes them on the way up? and on the way down? |
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2. I shoot a ball from a cannon at 15.0 m/s at 60.0 degrees
above the horizontal. It lands on a platform that is 8.00 m vertically above
the end of the cannon. Find the horizontal distance from the end of the cannon
to the point where the ball hits.
3. I throw a snowball from a roof 16.0 m high at 37 degrees above the horizontal. It lands 25.0 m away horizontally. Assume free fall. What is the initial speed of the ball?
4. I throw a snowball from a roof 16.00 m high with a velocity
of 15.00 m/s at some angle above the horizontal. The angle it is thrown at is
(37° ± 2°). Assume free fall.
(a) Where does the ball land horizontally?
(b) What is the velocity of the ball as it hits? Give the answer using unit vectors and also as a magnitude and direction.
We want an idea of the uncertainty in the answers. Different groups should use different angles. Each table should do two of the three possible angles, 35°, 37°, and 39°
5. Now you throw the same snowball from the same roof but
now you throw it down, at an angle of 17.0 degrees below the horizontal. Assume
free fall. (a) Where does the ball land horizontally? (b) What is the velocity
of the ball as it hits? Give the answer using unit vectors and also as a magnitude
and direction. (c) If the angle were the same as that in the previous problem,
would your answer to part (a) in the previous problem be the same as your answer
to (a)? What about for part (b)?
6. You get the opportunity to play pro-basketball with Michael Jordan.
The team is down by 2 points with time running out. Michael feeds you the ball
and you take a shot with 0.82 seconds remaining. It goes in, with nothing but
net, as the buzzer sounds! As with all your shots, the ball leaves your hand
at an angle of 30 degrees from the horizontal. Does the game go into overtime
or have you won?
| 7. A 2002 commercial showed a Kia driver trying to jump a chasm.
The car drives off the left portion of a bridge that is angled at 8°
above the horizontal, and just misses the right portion of the bridge located
a distance W = 6.0 m away. Instead the car crashes at the base of the chasm,
at H = 8.0 m below the receiving bridge. Assume you were hired to stage
this stunt. For safety reasons you want the right bridge abutment to just
pass above the windshield of the car. You must tell the stunt driver how
fast to drive (in miles per hour!) when he leaves the bridge, and you want
to know the speed of the car (in miles per hour!) when it crashes into the base of the chasm. The props department also need to know how long the receiving bridge must jut out past the crash point. |
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8. From Cummings et al. p. SP-19 5-3 Who killed Adam Able?
A person shoved out a window makes just as good a projectile as a golf ball
rolling off a table. You should read the murder mystery in the book / on your
handout. In order to solve the crime, you need to figure out what information
given is important and relevant. Also, some information is missing. You go into
the physics lab and shove your partner fairly hard in front of a motion detector.
The computer graph gives you a speed of about 2 m/s. Now figure out "Who
killed Adam Able?" ...
This page maintained by Anne G. Young. Last modified 27-Sep-2004 .