Motion
What is the rate of change in velocity
accceleration
Which law is associated with inertia?
1st
1. If the truck has a mass of 2,000 kilograms, what is its momentum? (v = 35 m/s)
70,000
what is force
A push or pull that acts on an object
Objects with a lot of ____________, have a lot
of motion.
momentum
true or false: an object slowing down is still accelerating
true
What law is known as the law of action-reaction?
A man hits a golf ball (0.2 kg) which accelerates at a rate of 20 m/s2. What amount
of force acted on the ball?
4
a Force that opposes the motion of
objects that touch as they move past
each other
friction
Objects with a greater __________ have greater
momentum.
mass
As a roller-coaster car starts down a slope, its
speed is 4 m/s. But 3 seconds later, at the
bottom, its speed is 22 m/s. What is its
average acceleration?
Acceleration = (22 m/s – 4 m/s)/3 s = 18 m/s/3 s
Acceleration = 6 m/s2
Forces are unbalanced when the net force is
not 0
Pete is driving down 7th street. He drives 200 meters in 18 seconds. Assuming he does not speed up or slow down, what is his speed in meters per second?
11.1
Force that acts between
two masses. Attractive force, Pulls objects together
gravity
in terms of force, if you increase an objects mass you increase____
acceleration.
If a speeding train hits the brakes and it
takes the train 39 seconds to go from 54.8
m/s to 12 m/s what is the acceleration?
12 m/s – 54.8 m/s ÷ 39 s = -42.8 m/s ÷ 39 s
= -1.097 m/s2
The second law states that the acceleration of an object is
dependent upon two variables
what are they
net force and mass
What is the unit for force
newton
Measure of inertia of an object and
depends on the amount of matter the
object contains
mass
what is The Law of Conservation of
Momentum
says that momentum does
not change when objects interact, it
remains the same before and after the
interaction.
What does it mean when an objects acceleration is negative
slowing down
The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object ___________ the size of the force on the second object. The direction of the force on the first object is __________ to the direction of the force on the second object.
equal, opposite
what is the unit for momentum
kgXm/s
___________causes objects to
accelerate downward
gravity
Which has more momentum, a 3 kg
sledgehammer (a) swung at 1.5 m/s, or
a 4 kg sledgehammer (b) swung at 0.9
m/s?
(a) 3 kg x 1.5 m/s = kg x m/s
(b) 4kg x 0.9 m/s = kg x m/s
A has more momentum than the heavier
one, because it is swung with a greater
velocity – almost twice as fast!