Units and Definitions
This is the standard SI unit for linear momentum.
What is the kilogram meter per second (kg⋅m/s)?
This physical quantity is defined as the product of the average net force acting on an object and the time interval over which the force acts.
What is impulse?
This is the magnitude of the linear momentum, in kg⋅m/s, for a 2.0 kg textbook thrown with a velocity of 3.0 m/s.
What is 6.0 kg⋅m/s?
This theorem relates the impulse exerted on an object to the object's change in momentum.
What is the Impulse-Momentum Theorem?
The Law of Conservation of Linear Momentum states that the total momentum of a closed, isolated system remains _______________.
What is constant (or conserved)?
This term describes linear momentum as having both magnitude and direction.
What is a vector quantity?
For a soccer ball subject to a net force of 50 N for 0.20 s, this is the magnitude of the impulse exerted.
What is 10 N⋅s?
A 0.15 kg baseball initially moving at 40 m/s is hit and leaves at 50 m/s in the opposite direction; this is the magnitude of the change in momentum.
What is 13.5 kg⋅m/s?
This is the final step in using the Impulse-Momentum Theorem to calculate the average force exerted on a ball, after finding the change in momentum.
What is dividing the change in momentum (Δp) by the contact time (Δt)?
A 60 kg student on ice throws a 5.0 kg bowling ball forward at 6.0 m/s; this is the magnitude of the student's recoil velocity in m/s.
What is 0.50 m/s?
This is the SI unit for impulse, which is dimensionally equivalent to the unit of momentum.
What is the Newton-second (N⋅s)? Accept kg⋅m/s
This quantity, according to the impulse-momentum theorem, must decrease if the collision time is increased while the impulse remains constant.
What is net force / sum of forces?
The momentum, in kg⋅m/s, of a 50 g golf ball traveling at 70 m/s.
What is 3.5 kg⋅m/s?
This is the condition that must be met for the total momentum of a system to be CONSTANT.
What is the system must be isolated / the net external force must be zero?
If two identical railroad cars, one moving at velocity v and one at rest, collide and couple, this is the final velocity of the coupled cars in terms of v.
What is v/2?
The physical quantity represented by the product of an object's mass and its velocity.
What is linear momentum?
This is the amount of time, in seconds, over which a 20 N force must act to provide an impulse of 5 N⋅s.
What is 0.25 s?
If an object's momentum increases by 10 kg⋅m/s and its mass is 2 kg, this is the magnitude of the change in its velocity.
What is 5 m/s?
The relationship that mathematically equates impulse (J) to the initial and final momentum.
What is J = pf - pi (or FΔt=Δp)?
A 1500 kg car at 20 m/s collides head-on and sticks to a 1000 kg car at 15 m/s in the opposite direction; this is the final velocity.
What is 3.0 m/s in the initial direction of the 1500 kg car?
This describes an idealized system in which no external forces, such as friction or air resistance, act on the objects within it.
What is a closed, isolated system? Accept closed OR isolated
The main reason padding and crumple zones are used in safety equipment is to increase this quantity during an impact, thereby decreasing the average net force.
What is the collision time (or time interval)?
The total momentum of a 10 kg bowling ball moving East at 4 m/s and a 5 kg bowling ball moving West at 4 m/s.
What is 20 kg⋅m/s East?
A rocket firing its engine to accelerate uses this fundamental principle to explain why the rocket moves forward.
What is the Impulse-Momentum Theorem (or Conservation of Momentum)?
In an explosion where a stationary object breaks into two pieces, this is the total final momentum of the two pieces immediately after the explosion.
What is zero?