Momentum

Question 1

what is momentum defined as

Answer 1

the product of the objects mass and velocity

Question 2

what is the formula for momentum

Answer 2

momentum = mass x velocity
p = m * v

Question 3

how can the momentum of an object be increased

Answer 3

• by increasing the mass of the object

- or by increasing its velocity

Question 4

what type of quantity is momentum

Answer 4

• a vector quantity

- so its a quantity with a size and direction

Question 5

a 50kg cheetah is running at 60m/s. calculate its momentum

Answer 5

p = m * v
momentum = 50kg x 60m/s
= 3000kg m/s

Question 6

a boy has a mass of 30kg and a momentum of 75kg m/s. calculate his velocity

Answer 6

p = m * v
so v = p / m
75 / 30 = 2.5m/s

Question 7

what is momentum like in a closed system

Answer 7

• the total momentum before an event is the same as after the event
• no momentum (energy) is lost or gained

Question 8

what could an ‘event’ be regarding how momentum might be changed

Answer 8

a collision, as velocity would be changed

Question 9

what is the conversation of momentum

Answer 9

the total momentum before an event is the same as after the event

Question 10

a red ball is stationary and a white ball is moving with a velocity. explain the changes in momentum in the balls and in general as they collide. the balls are the same size and mass

Answer 10

• as the white ball has a velocity ( and a mass) it has momentum
• white ball hits read ball causing it to move
• red ball has a momentum now (velocity and mass)
• white ball keeps moving but at a smaller velocity, so less momentum
• momentum of white and red ball has changed in the collision (event) due to a change in velocities
• but the combined momentum of the red and white ball equals the original momentum of white ball

Question 11

in a collision, why does the combined momentum of a red and white ball equal the original momentum of the ball that hit the other ball in the first place

Answer 11

• because of the conservation of momentum

- which states that the momentum before an event is equal to the the momentum after n event, in a closed system