Motion and Forces
Causes objects to have constant velocity (State whether the following is true for Balanced Forces, Unbalanced Forces or All Forces by writing Balanced, Unbalanced or All on the lines.)
Balanced
Net force=0 ( State whether the following is true for Balanced Forces, Unbalanced Forces or All Forces by writing Balanced, Unbalanced or All on the lines.)
Balanced Forces
Will not change an object's motion
Balanced Forces
What does it mean to have a constant velocity? Are there balanced or unbalanced forces while there is constant velocity?
Constant velocity occurs when an object's speed and direction of motion do not change. There is no change in its motion (no acceleration). There are BALANCED forces acting on an object moving at a constant velocity.
What is Newton's 3rd law?
Each action, or force, has an equal and opposite reaction
Push or Pull
Force
How is mass related to Inertia?
Higher mass=higher inertia
Describe how to combine unequal forces acting in opposite directions.
I subtracted the smaller force from the larger force. ( Add forces going in the same direction together.)
2 ways to increase acceleration.
Increase Force and Decrease Mass
Acceleration(unit)
M/S/S
What is the Conservation of Momentum?
Momentum before a collision is equal to the momentum after a collision. Momentum is transferred (Newton's Cradle)
Force(unit)
N
The sum of all forces acting on an object
Net Force
The SI unit for force
Newton
Describe in your own words how Newton's 3rd Law can be applied to football:
Newton's third law of motion is naturally applied to collisions between two players. In a collision between two players, both players experience forces that are equal and opposite in direction. Such forces often cause one object (or player) to speed up (gain momentum) and the other object (or player) to slow down (lose momentum). Having more mass or more velocity will give you more momentum.
What is the formula for Momentum?:
P(momentum)=m(mass) x (v)velocity
Why is Newton's first law of motion sometimes called the law of inertia?
Part of Newton's law is that an object at rest stays at rest, and then inertia is an object's reluctance to move.
What is recoil? Which of Newton's Laws does it relate to?
Recoil is the backward movement of a gun when it is discharged._It relates to Newton's 3rd law because it is the reaction to the action of the force required to fire the gun.
How did the woman in this video apply a greater force than the man? Describe what she did.
She stepped back and pulled her arm back further, then twisted into her swing, giving her more distance to travel and more time for her fist to accelerate. By increasing her acceleration, she was able to match and even exceed the force of the man with greater muscle mass.
Why is it important for drivers to allow more distance between their cars when they travel at faster speeds?
Take longer to stop the forward momentum and you might crash into car in front if too close to them.
State Newton's second law of motion in your own words.
The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
Using what you know about Newton's second law, explain why a car with a large mass might use more fuel than a car with a smaller mass. Assume both cars drive the same distance.
The car with more mass will use more fuel because it will accelerate more which will burn more fuel.
What is momentum?
The quality of motion of a moving body, measured as a product of its mass and velocity.
What is conservation of momentum?
The total amount of momentum is conserved when objects collide
What three rules must one follow to avoid being thrown back from recoil?:
To avoid being thrown back hold a stable position, lean forwards, and hold the gun tightly to the shoulder.
Causes objects to accelerate (State whether the following is true for Balanced Forces, Unbalanced Forces or All Forces by writing Balanced, Unbalanced or All on the lines.)
Unbalanced
Net force does not = 0 (State whether the following is true for Balanced Forces, Unbalanced Forces or All Forces by writing Balanced, Unbalanced or All on the lines.)
Unbalanced
Can change an object's motion
Unbalanced Forces
What is Newton's 1st Law?
What is Newton's 1st Law?
How could you keep an object's acceleration the same if the force acting on the object were doubled?
You can double the mass of the object.
Use what you know about inertia to explain why you feel pressed back into the seat of a car when it accelerates.
Your back presses against the car because of inertia you do not move right away.
Acc. formula
a=f/m
force formula
f=ma
Mass(unit)
kg
mass formula
m=f/a
Acceleration of an object depends on
mass and net force
The total momentum of two marbles before a collision is 0.06 kg·m/s. No outside forces act on the marbles. What is the total momentum of the marbles after the collision?
0
What is the momentum of a parked car?
0 m/s
A book rests on top of a shelf and does not move until a student accidently knocks it off. (newtons 1,2, or 3)
1
A magician pulls a tablecloth out from under a dish on a table without disturbing the dish. (newtons 1,2, or 3)
1
Water spills from a glass carried by someone who is walking steadily and suddenly stops short. (newtons 1,2, or 3)
1
1 Newton is equal to the froce needed to...
1 kg x m/s/s
A pitcher throws a 142 g baseball, which accelerates at a speed of 9 m/s^2. How much force does the pitcher apply to the ball?
1.28 N
What is the net force acting on a 0.15-kg hockey puck accelerating at a rate of 12 m/s2?
1.8 N
A bowler rolls a 5 kg bowling ball down a magical frictionless bowling alley. The ball accelerates at an average rate of 2 m/s^2. How much force did the bowler apply to the ball?
10 N
Pushing a baby on a swing is easier than pushing an adult on the same swing (newtons 1,2, or 3)
2
When thrown with the same force, a soccer ball accelerates more than a bowling ball. (newtons 1,2, or 3)
2
What is the momentum of a 920-kg car moving at a speed of 25 m/s?
23,000 m/s
A rocket launches into space, pushing fuel exhaust in one direction and the rocket in the opposite direction. (newtons 1,2, or 3)
3
A kid applies a force of 27 newtons to a 9 kg wagon. How fast does it accelerate?
3 m/s^2
Find the force it would take to accelerate an 800-kg car at a rate of 5 m/s2.
4000 N
0.048 newtons of force are applied to a 12 g weight, which slides across a frictionless surface. How fast does the weight accelerate?
4m/s^2
Which has more momentum: a 250-kg dolphin swimming at 4 m/s, or a 350-kg manatee swimming at 2 m/s?
A dolphin
What is an unbalanced force? Give an example.
A force exerted on an object that causes it to change its speed or direction. Like when a lineman collides with a Quarterback
Describe in your own words how Newton's 1st Law can be applied to football (be sure to include the role of mass and inertia in your explanation):
A player with more mass will have more inertia and be able to resist the unbalanced forces acting on them from other players.
What is Inertia?
A tendensy to resist
What does it mean to accelerate? Are there balanced or unbalanced forces during acceleration?
Acceleration means that the velocity of an object is changing over time. The object can be speeding up, slowing down or changing direction. There are UNBALANCED forces during acceleration.
Explain how, despite having less muscle mass, a person may be able to apply more force than someone with greater muscle mass.
According to F=ma, you can increase the amount of force you apply even if you have a smaller mass, by increasing your acceleration
What would happen if you tried to catch a ball when you were standing on roller skates?
After you catch the ball, the ball's motion would act on you and you would move backward
A push or a pull (State whether the following is true for Balanced Forces, Unbalanced Forces or All Forces by writing Balanced, Unbalanced or All on the lines.)
All
Have direction (State whether the following is true for Balanced Forces, Unbalanced Forces or All Forces by writing Balanced, Unbalanced or All on the lines.)
All
What does Newton's first law of motion state?
An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
What is needed to start an object moving?
An unbalanced/outside force
