What is a PUSH or PULL on an object?
Force
Give an example of a force.
anything that is a push or a pull
What do we call the force that acts directly against the direction of motion, usually when two surfaces come in contact and rub against each other?
Friction
A golf ball rolls down a hill on the golf course. Which statement best describes how friction affects the motion of the golf ball?
A. Friction causes the golf ball to roll forwards and backwards.
B. Friction decreases how far the ball rolls.
C. Friction increases how fast the ball rolls.
D. Friction causes the ball to bounce.
B. Friction decreases how far the ball rolls.
What do we call the force that pulls objects towards Earth's center?
gravity
If these boys are each pulling with the force of 10 newtons. What will happen?
The boy in blue will win.
They will not move at all.
The boy in red will win.
They will not move at all. Balanced force is being applied.
If a giant gorilla is leaning on a wall the force being put on the wall is _____________________ to the force being added by the gorilla.
Equal
What is a change in the speed of an object considered?
ACCELERATION
What is constant speed?
1.When the speed of an object stays the same.
2.When the speed of an object increases.
3.When the speed of an object decreases.
1.When the speed of an object stays the same
Give an example of an object with low mass AND an object with high mass.
low mass= light weight
high mass= heavy
Which of the following statements is true?
Balanced forces cause a change in position.
Unbalanced forces cause a change in position.
Forces do not affect position.
Unbalanced forces cause a change in position.
What is the 2nd force in this example:
When playing a piano your fingers push down on the keys.
The piano keys push back up on your fingers with equal force.
What is a change in direction called?
acceleration
I have a change in speed, but NOT direction, is this acceleration? Yes or no?
Yes
A person is running down the hall at 2MPH, give an example of this person changing their motion.
Any answer where the person is not running at the same speed.
What is the formula for Newton's second law of motion?
F=M*A
What is the equation to calculate speed?
speed = distance / time
If a ball is rolling, what is a large change in motion?
To slow down, but still be rolling.
To run into a wall and stop.
To keep rolling at the same speed.
To run into a wall and stop
Which car have a greater change in motion in a collision (crash)?
1. a car with low mass
2. a car with high mass
3. a car with medium mass
1. a car with low mass
In outer space, an object's ______ changes, but its _______ stays the same.
1. weight, mass
2. mass, weight
1. weight and mass
What does Newton's first law state?
An object at rest (in motion) will stay at rest (in motion) unless acted on by another force.
IF 5 students push a block to the East with a force of 12 newtons and were joined by 3 more students who contributed 8 more newtons but were opposed by 7 students pushing the block westward with a force of 18 newtons, which direction would the block move?
The block would move to the east.
True/False:
Action and reaction forces (Newton's 3rd law) are ALWAYS equal in size and opposite in direction.
True
Using Newton's 2nd Law, what is the acceleration of an object with a mass of 10kg, and a force of 100 N?
10 m/s2
What is the speed of a train that covers 200 km in 2 hours?
200 / 2 = 100 km/hr
What did we learn in Activity 3?
We learned that the faster an object moves the more kinetic energy it has.
IF 5 students push a block to the East with a force of 15 newtons and were joined by 3 more students who contributed 8 more newtons but were opposed by 7 students pushing the block westward with a force of 18 newtons, what is the net force and in what direction?
A net force of 5 eastward
What is the basic understanding of Newton's 3rd law of motion?
For every action there is an equal and opposite reaction.
What did we learn in Activity 6?
For an object to change direction a force must be applied.
What is the average speed of a train that covers 80km in 1 hr, then 200 km in 2 hrs, and then 240 km in 2 hrs?
80/1 = 80
200/2 = 100
240/2 = 120
80+100+120 = 300
300/3 = 100km/hr