Force
If you increase the force on an object what happens to the acceleration?
It increases
Which law is associated with inertia?
Newton's first law
What is Newton's second law in your own words.
Objects with more mass take more force to move, lighter objects will move faster with the same force
What is Newton's third law
For every action there is an equal and opposite reaction.
Mr. Smith and his wife were trying to move their new chair. Mr. Smith pulls with a force
Of 30 N while Mrs. Smith pushes with a force of 25 N in the same direction. What is the net
force?
50 N in the same direction
If an object is not accelerating what can you determine about the sum of all the forces on the object?
The net force is zero or they are balanced forces
Velma drives to work each day and places her bag on the seat before she leaves. By the time she gets to work the bag is on the floor. Explain why this is.
When Velma comes to a stop her bag is still moving at the same speed as the car. Since her bag is not secured in the seat the inertia of the bag makes it wan tto keepp moving and falls on the floor.
If you double the force of an object what happens to the acceleration?
The resulting acceleration doubles as well
A diver dives off of a raft - what happens to the diver? The raft? How does this relate to Newton's Three Laws?
Action Force: _______________ Reaction Force: _____________
Action: diver pushing off the raft
Reaction: Raft pushing off the diver
What is the rate of acceleration of a 2,000-kilogram truck if a force of 4,200 N is used to make it start moving forward?
2.1 m/s
How much force is needed to accelerate a 69 kilogram-skier at a rate of 1.2 m/sec2
82.8 N
Does everything have inertia?
Does everything have momentum?
What is the difference?
Yes
No
To have momentum you have to have motion
What is the acceleration of a 6.4 kilogram bowling ball if a force of 12 N is applied to it?
1.88 m/s
If I am pushing on the wall and the wall is pushing on me what comes first, the action or reaction and which is which?
The action comes first
Action: Me pushing on the wall
Reacction: The wall pushin on me
How fast has someone traveled if it took them 3 hours to go 275 km.
91.66 kmh
Explain what causes an object to slow down or speed-up and why does this happen?
Unbalanced force. Objects in motion stay in motion unless acted on by an outside force
Which law explains why a coin will fall into a cup if a card is knocked out from under it? Explain what is happening causing the coin to stay.
The first law, The card moves so fast that inertia of the coin is making it want to stay where it is. once the card is gone gravity puls it down.
If you triple the mass of an object what happens to the acceleration?
The resulting acceleration is cut in third or 1/3 or cut by a factor of three
What forces are acting on a book sitting on a table? Are action-reaction forces involved in this
Situation and why?
Balanced forces
Yes
the force of the book pushing down on the table (action) and the force of the table pushing back on the book (Reaction)
How far has a person traveled if they are traveling 95 km/h for 120 minutes?
190 Km
While driving down the road, a firefly strikes the windshield of a bus and makes a quite obvious mess in front of the face of the driver. This is a clear case of Newton's third law of motion. The firefly hits the bus and the bus hits the firefly. Which of the two forces is greater: the force on the firefly or the force on the bus? Explain.
The resulting action reaction forces are the same but becasue the mass of the bus is so much larger the bug plats on the windshiled instead of the windshield breaking from the bug.
Ben Tooclose is being chased through the woods by a bull moose which he was attempting to photograph. The enormous mass of the bull moose is extremely intimidating. Yet, if Ben makes a zigzag pattern through the woods, he will be able to use the large mass of the moose to his own advantage. Explain this in terms of inertia and Newton's first law of motion.
The mass of the mooses is so large that an object in motion tends to stay in motion. Since the mass of the moose is large when Ben turns the moose will take longer to turn because his inertia is moving one direction and will want him to keep going in that direction.
Many people are familiar with the fact that a rifle recoils when fired. This recoil is the result of action-reaction force pairs. A gunpowder explosion creates hot gases which expand outward allowing the rifle to push forward on the bullet. Consistent with Newton's third law of motion, the bullet pushes backwards upon the rifle. The acceleration of the recoiling rifle is ...
a. greater than the acceleration of the bullet.
b. smaller than the acceleration of the bullet.
c. the same size as the acceleration of the bullet.
Explain your answer.
B.
The mass of the bullet is much smaller than the mass of the gun. Since they are both experiencing the same force the one with the smaller mass will accelarate more.
If two people, with the same mass each standing on a skateboard push off of each other what happens?
They would both accelarate away form eachother and the same rate and distance.
The classes are playing tug of war. Mrs. Larson’s homeroom pulls with a force of 50 N.
Ms. Mitko’s homeroom pulls with a force of 45 N in the opposite direction. What is the net
Force? And who won?
5 towards Mrs. Larson's class and Mrs. Larson's class won.