Momentum Flashcards
(13 cards)
What does higher mass and velocity result in?
A higher mass and higher velocity will result in a larger momentum.
Is momentum a scalar or vector quantity?
Momentum is a vector quantity, as it has both magnitude and direction.
What happens to momentum during a collision or explosion?
Momentum is conserved during a collision or explosion if no external forces act on the object.
What does the conservation of momentum mean?
The conservation of momentum means that the total momentum before a collision will be the same after the collision.
What does Newton’s second law of motion state?
Newton’s second law of motion states that the rate of change of momentum is proportional to the size of the force acting on the object.
How can you change the momentum of an object?
To change the momentum of an object you can apply a small force over a long time, or a larger force over a shorter time.
Why is it important to increase the time taken to bring a car to rest in a crash?
During a car crash the car decelerates and comes to a stop very quickly, meaning the time to change momentum is short. The equation shows that a short time leads to a larger force. To reduce injury, the time taken to stop is increased by using seat belts, air bags, and crumple zones to reduce the force on passengers.
What does Newton’s third law state?
Newton’s third law states that when two objects interact they exert equal and opposite forces on each other.
What is a moment?
A moment is the turning effect of a force. For example pushing bike pedals creates a moment that turns the bike wheels.
What are moments?
Moments act about a point (called the pivot) in a clockwise or anticlockwise direction.
How do levers work?
Levers increase the turning effect of a force by increasing the distance between the force applied and the point at which the object turns.
What does it mean when an object is balanced?
If an object is balanced this means that the turning effect acting in the clockwise direction is equal to the turning effect in the anticlockwise direction.
What happens when two people of equal weight sit at equal distances from the pivot on a see-saw?
Let’s say if two people of equal weight are sat at equal distances from the pivot on a see-saw the clockwise and anticlockwise moments will be balanced and the see-saw will stay still.
