Download Exam 2

1. A 55 kg human cannonball is shot out the mouth of a 4.5
m cannon with a speed of 18 m/s at an angle of 60°.
(Neglect friction and air resistance in this problem.)
Determine…
a. The magnitude of the acceleration of the human
cannonball inside the barrel.
b. The force on the feet of the human cannonball
while she is being launched.
2. A 100 kg wooden crate rests on a wooden ramp with an adjustable angle of inclination.
a. Draw a free body diagram of the crate
b. If the angle of the ramp is set to 10°, determine the static friction force between the crate
and the ramp.
c. At what angle will the crate just begin to slip?
d. If the angle of the ramp is set to 30°, determine the acceleration of the crate.
3. A laboratory cart (𝑚1 = 500 g) rests on an inclined track (Θ = 9°). It is connected to a
lead weight (𝑚2 = 100 g) suspended vertically off the end of a pulley as shown in the
diagram below. The system is released and the cart accelerates up the incline. (Assume
the string and the pulley’s mass is negligible and that friction is small enough to ignore.)
Draw a free body diagram for…
a.
The cart.
b.
The lead weight
Determine…
c.
The acceleration of the system
d.
The tension in the string.
4. A 250 kg motorcycle is driven around a 12 meter tall vertical circular track at a constant
speed of 11 m/s.
a. Determine the normal and friction forces at the four points labeled in the diagram
below.
i. At the bottom (and rising)
ii. Halfway to the top
iii. At the top
iv. 45° past the top
b. Determine the minimum coefficient of static friction needed to complete the stunt
as planned.
(The given mass includes the mass of the rider already. Assume drag and any rotational
resistance are negligible.)
5. An 11.3 g bullet leaves the muzzle of a 61 cm rifle with a horizontal velocity of 922 m/s.
-Determine…
a. The acceleration of the bullet in the rifle
b. The force of the propellant on the bullet in the rifle
c. The work done on the bullet while it is in the barrel.
--The bullet strikes a target 457 m away with a horizontal velocity of 650 m/s.
Determine…
d. The horizontal acceleration of the bullet as it flies through the air
e. The force of drag on the bullet
f. The work done by aerodynamic drag on the bullet.
6.