Tuesday January 13
Whiteboard Game!
Rules of the game…
• You are working as a table to solve each
problem. You need to show ALL of your work:
in this case, fill in the IF (initial-final) chart
AND show your work with the conservation of
momentum equation.
• The first three tables with complete and
correct work with an answer receive
Martinsek Money for the question.
Set up your whiteboard!
You need to have the following setup on your
whiteboard (maybe divide the whiteboard into
three sections for initial, final, then the
equation).
Sketch of Initial Situation
Sketch of Final Situation
event:
initial
final
mass/object/velocity
0
Momentum conservation equation:
mass/object/velocity
+
-
0
+
Question 1
Old cannons were built on wheeled carts, both
to facilitate moving the cannon and to allow the
cannon to recoil when fired. When a 150 kg
cannon and cart recoils at 1.5 m/s, at what
velocity would a 10 kg cannonball leave the
cannon? Both cannonball and cannon start at
rest.
Question 2
On an icy road, a 5000 kg truck rear-ends a 1200
kg car that had been traveling at 13 m/s, causing
the truck to slow from 14 m/s to 12 m/s and the
car to speed up. How fast was the car moving
after the collision?
Question 3
A cart of mass 3.0 kg, moving at 2 m/s to the
right, strikes head-on a cart of mass 1.0 kg that
is moving at 2 m/s to the left. The carts stick
together after the impact. What is the
magnitude (amount) and direction of the
velocity of the combined mega car after the
collision?
Question 4
One way of measuring the muzzle velocity of a
bullet is to fire it horizontally into a massive block of
wood placed on a cart. Assuming no friction, we can
then measure the velocity of the wood, bullet, and
cart as they begin to move.
In one experiment, the bullet had a mass of 0.05 kg
and the wood and its cart had a mass of 20 kg. After
the shot, the cart + wood + bullet moved at a
constant speed traveling 8 m in 4 s. Determine the
original speed of the bullet.
Question 5
A raft of mass 180 kg carries two swimmers of
mass 50 kg and 80 kg. The raft is initially floating
at rest. The two swimmer simultaneously dive
off opposite ends of the raft, each with a
horizontal velocity of 3 m/s. Determine the final
velocity and direction of the raft.