Vocabulary and Thinking Problems
A ball experiences a loss of 20 kg m/s of momentum. If its final momentum is 10 kg m/s, what was its original momentum?
What is 30 kg m/s?
What equals the momentum change in an object?
What is impulse
Boulder A falls off a cliff. If Boulder B then falls off the same cliff at the same height, but is half as large as the Boulder A, which will have more momentum?
What is Boulder A-it has greater mass so has more momentum. The speed should be equal.
If two pieces of pizza dough (with equal mass) are thrown at each other (at equal velocity), and stick together, what will their new velocity be?
What is zero.
T/F: It is better to decrease the time of impact in a collision for the safety of the passengers in a car.
What is FALSE-it is better to increase the time of impact in a collision. Thus, the longer the impact, the less the force.
T/F: Momentum in a system is always conserved for both recoil situations and elastic/inelastic collisions.
What is TRUE? Conservation of momentum means that the momentum before and after is the same.
A 5kg baseball is throw 5 m/s. What is the momentum?
What is 25 kg x m/s
T/F: When comparing an egg thrown at a bedsheet and an egg thrown at the wall, the reason the egg thrown at the wall breaks is because it has a larger impulse on it.
What is false. The egg thrown at the wall and the egg thrown at the bedsheet have the same exact impulse. The egg hitting the wall has a smaller time, thus a much larger force.
Where is the most unsafe place to stand when firing a cannon that is lighter than the cannonball?
What is behind the cannon ( it will shot back and knock you down due to the momentum of the cannonball.
When a gymnast sticks a landing (lands with straight legs and no bent knees), the force on the gymnast's body is greater, lesser, or equal to the force if he/she landed with slightly bent knees.
What is greater. If you do not bend your knees the time of impact is reduced, which causes greater force.
An ice skater on the ice is not allowed to use their legs to skate, but has to try to reach the other side of the ring. Using momentum, how could he/she accomplish this?
What is the skater could throw objects in the opposite direction he/she needs to go.
A stationary 1 kg ball is hit by a force of 25 N giving it a final velocity of 15 m/s. Which statement is true:
a) The impulse cannot be determined as we don't know the time
b) The impulse can be determined by calculating the change in momentum.
What is B? Impulse and change in momentum are always equal.
Which has greater momentum on a frictionless surface? A. A women and her younger daughter colliding on ice and bouncing off of each other, or B. If they hung onto each other and continued on?
What is B-their mass would increase, which would increase their speed on the surface and thus increase momentum.
A 10 kg blob of cookie dough is moving at a speed of 5 m/s and hits a 5 kg blob of cookie dough that it at rest. What is the speed of the cookie dough if they stick together after the collision?
What is 3.3. m/s?
An astronaut floating motionlessly in space throws a space rock (which has more mass than him). Which will move faster through space?
What is the astronaut.
Explain using the concepts of momentum how an airbag makes a vehicle safer. You MUST be specific with the concept of impulse.
What is extends the impact time to reduce the force. The impulse cannot be changed as you will be losing all of your momentum due to the crash.