Impulse Momentum and Energy Transformation

Question 1

efficiently elastic material example

Answer 1

rubber
steel
cork

Question 2

one that has the right combination of strength and elasticity for a particular application

can regain their shape after being stretched or compressed

Answer 2

efficiently elastic material

Question 3

mass in motion

Answer 3

momentum

Question 4

intertia in motion

Answer 4

momentum

Question 5

a lot of momentum means a lot of ___

Answer 5

oomph

Question 6

momentum formula

Answer 6

mass x velocity

Question 7

two types of momentum

Answer 7

linear momentum
angular momentum

Question 8

angular momentum formula

Answer 8

L = Iw

Question 9

SI unit of momenntum

Answer 9

kg m/s

Question 10

the direction of the momentum is the same as ___

Answer 10

velocity

Question 11

a vector that points in the same direction as the object’s velocity

Answer 11

monemtum

Question 12

as such we can also write the momentum in terms of x and y components that is

Answer 12

px = mvx

py = mvy

Question 13

he momentum towards the __and ___will have a negative sign.

Answer 13

left
down

Question 14

what is newton’s second law of motion

Answer 14

an object acted upon by a constant unbalanced force, moves with constant acceleration in the direction of the unbalanced force

Question 15

newton’s second law of motion formula

Answer 15

Funb = ma

Question 16

to rewrite momentum in terms of newton’s second law of motion:

Answer 16

F = ma
F = m Δv/t = mΔv/t
Ft = mΔ

Question 17

ft = Δ(mv) is also known as

Answer 17

impulse

Question 18

change in momentum

Answer 18

impulse

Question 19

impulse unit

Answer 19

J

Question 20

is defined as the change in momentum of an object due to a force that is applied during a period of time

Answer 20

impulse

Question 21

aside from J, impulse also the unit

Answer 21

N s

Question 22

sually considered typically during collision (short period) or explosion

Answer 22

impulse

Question 23

states that an impulse delivered to an object causes the object’s momentum to change.

Answer 23

momentum principle

Question 24

a 1.3kg ball is coming straight at a 75 kg soccer player at 13 m/s who kicks it in the exact oppositedirection at 22 m/s with an average force of 1200N. How long are his foot and the ball in contact?

Answer 24

0.0379s

Question 25

product of the force acting on an object over time during which the force acts

Answer 25

impulse

Question 26

impulse momentum theorem formula

Answer 26

F = mΔv/t

Question 27

impulse applied to the object is equal to the ___

Answer 27

change in momentum

Question 28

states that the total momentum of an isolated system remains constant, unless an external force acts upon it

Answer 28

law of conservation of momentum

Question 29

law of conservation of momentum formula

Answer 29

mava + mbvb = mava + mbvb

Question 30

law of conservation of momentum states

Answer 30

in a closed and isolated system, the total momentum of the objects before a collision is equal to the total momentum of the objects after the collission

Question 31

system where matter and energy do not enter or leave the system

Answer 31

closed, isolated system

Question 32

is a brief interaction between two (or more) objects

Answer 32

collission

Question 33

the word __ is used when the interaction time (Δt) is short relative to the rest of the motion

Answer 33

collission

Question 34

during a collision, the objects exert equal and opposite forces on each other, we assume these "internal" forces are much larger than any ____ on the system

Answer 34

external

Question 35

three types of collission

Answer 35

perfectly inelastic elastic inelastic

Question 36

two object stick together after the collision so that their final velocities are the same

Answer 36

perfectly inelastic

Question 37

conserved quantity in perfectly inelastic collision

Answer 37

momentum

Question 38

the two objects bounce after the collision so that they move separately

Answer 38

elastic collision

Question 39

what is conserved in elastic collision

Answer 39

momentum and kinetic energy

Question 40

the two objects deform during the collision so that the total kinetic energy decreases, but the objects move separately after the collision

Answer 40

inelastic collision

Question 41

conserved quantity in inelastic collision

Answer 41

momentum

Question 42

energy of motion

Answer 42

kinetic energy

Question 43

kinetic energy formula

Answer 43

1/2mv^2

Question 44

J is also known as

Answer 44

kg m^2/s^2

Question 45

two dimension collision of two objects formula

Answer 45

m1v1ix + m2v2ix = m1v1fx+m2v2fx m1v1iy+m2v2iy = m1v1fy+m2v2fy

Question 46

Which has a greater momentum—a truck with a mass of 2250 kg moving at a speed of 25 m/s or a car with amass of 1210 kg moving at a speed of 51 m/s?

Answer 46

car

Question 47

A car accelerates from rest. In doing so the absolute value of the car's momentum changes by a certain amount and that of the Earth changes by a larger amount.

Answer 47

False

Question 48

The impulse-momentum relationship is a direct result of

Answer 48

Newton's second law

Question 49

A 5000-kg freight car moving at 2 m/s collides with a 10,000-kg freight car at rest. They couple upon collision and move away at

Answer 49

2/3 m/s

Question 50

When a golf club hits a golf ball, the change in momentum of the ball is ___________ the change in momentum of the club.

Answer 50

equal to

Question 51

Consider two carts, of masses m and 2m, at rest on an air track. If you push first one cart for 3 s and then the other for the same length of time, exerting equal force on each, the kinetic energy of the light cart is smaller than the kinetic energy of the heavy car. T/F

Answer 51

False

Question 52

Suppose the entire population of the world gathers in one spot and, at the sounding of a prearranged signal, everyone jumps up. While all the people are in the air, Earth recoils, like a rifle firing a bullet, with a change in momentum equal to and opposite that of the people. T/F

Answer 52

True If we consider Earth to be an isolated system (during the short time interval that the people jump up, this approximation is appropriate), then momentum must be conserved. So the momentum of Earth must be equal to and opposite that of the jumping people. Because of Earth's large inertial mass, however, there is no perceptible motion.

Question 53

If superman at rest in free space throws an asteroid that has more mass than superman, then which moves faster?

Answer 53

superman

Question 54

A Toyota (small car) strikes a Mack truck (large truck) head-on. They stick together after the collision. Defining the system as the car plus the truck, total momentum and total energy are conserved. T/F

Answer 54

True Assuming that the drivers do not apply the brakes and thus the system is isolated, both total momentum and total energy are conserved. Some kinetic energy is dissipated into the deformation of the car and truck so kinetic energy is not conserved. Correct answer: True

Question 55

Padded dashboards in cars are safer in an accident than non-padded ones because passengers hitting the dashboard encounter

Answer 55

: lengthened time of contact

Question 56

A person is standing on a roller blades and is holding a heavy medicine ball. If he throws the ball horizontally to the right, what will be the resulting motion?

Answer 56

: to the left

Question 57

A large heavy truck and a small baby carriage roll down a hill. Neglecting friction, at the bottom of the hill,the baby carriage will likely have

Answer 57

less momentum.

Question 58

Whether a truck comes to a stop by crashing into a haystack or a brick wall, the impulse is

Answer 58

both the same

Question 59

A golf ball is fired at a bowling ball initially at rest and bounces back elastically. Compared to the bowling ball, the golf ball after the collision has less momentum but more kinetic energy. T/F

Answer 59

True The golf ball bounces back at nearly its incident speed, whereas the bowling ball hardly budges. Thus the change in momentum of the golf ball is nearly -2mv, and the bowling ball must gain momentum +2mv to conserve momentum. However, since the mass of the bowling ball is much larger than that of the golf ball, the bowling ball's velocity and hence its kinetic energy are much smaller than those of the golf ball.

Question 60

Skelly the skater travelling at high speed needs a certain amount of force to stop him. More stopping force is needed if he has

Answer 60

all of the above

Question 61

The momentum change of an object is equal to the

Answer 61

impulse acting on it

Question 62

A 90 kg halfback runs north and is tackled by a 120 kg opponent running south at 4 m/s. The collision is perfectly inelastic. Just after the tackle, both players move at a velocity of 2 m/s north. Calculate the velocity of the 90 kg player just before the tackle.

Answer 62

The velocity of the 90kg player just before the tackle is 10 m/s, North.