Download Grade 12 University Physics Tutorial 3 1. A ping pong ball (mass is

Grade 12 University Physics
Tutorial 3
1. A ping pong ball (mass is 15 grams) has an initial velocity of -0.5 m/s. As it makes contact with a
racket, the force the ball experiences is 0.2 N for 250 milliseconds. Determine the final velocity of the
ball (impulse).
2. A particle (mass is 2x10-27 kg, initially stationary) decays into 3 particles. Particle A (mass is 1x10-27kg)
has a velocity of 1m/s[N30W]. Particle B (mass is 0.25x10-27 kg) has a velocity of 3 m/s[S]. What is the
velocity of the 3rd particle (conservation of momentum)?
3. Two asteroids (mass is 1000 kg and 100 kg) are moving towards each other. The heavier asteroid has a
speed of 5000 km/hr. The lighter asteroid has a speed of 500 km/hr. After the collision, the heavier
asteroid has a speed of 4400 km/hr. Determine the velocity of the lighter asteroid (conservation of
momentum).
4. A roller coaster car (mass is 400 kg) has an initial speed of 15 m/s at the top of a crest. The coaster drops
a height of 20 meters and at the bottom of the track has a speed of 21 m/s. Determine the amount of
energy lost during the run.
5. A head on elastic collision occurs between objects A (mass is 5 kg) and B (mass is 2 kg). Object B is
initially stationary. After the collision, B is moving with a velocity of 3 m/s. Determine the speed of
object A after the collision.
6. A spring is initially compressed by 0.15 m and has a spring constant of 1000 N/m. A 1 kg block is
placed next to the spring. The angle the incline makes with the horizontal is 15 degrees. The force of
friction the block experiences while traveling along the incline is 2 N.
a) Calculate the initial energy of the block
b) Calculate the initial force acting on the block
c) Calculate the maximum distance the block travels along the incline
7. An arrow is fired at a styrofoam (mass is 2 kg) block (acting like a pendulum). The mass of the arrow is
15 grams, and travels with a velocity of 30 m/s prior to hitting the block.
a) Calculate the velocity of the arrow – block combination right after collision
b) Calculate the kinetic energy of the arrow block combination right after the collision
c) Calculate the maximum height the arrow block combination swings to (when the speed is 0)
d) Calculate the change in kinetic energy of the arrow block
e) Calculate the change in GPE of the arrow block
Answers:
1)
2)
3)
4)
5)
6)
7)
2.833 m/s
5500 km/hr
35200 J
a) 11.25 J
a) 0.22 m/s
b) 150 N
b) 0.05 J
c) 1.34 m
c) 0.0025 m