force
how do we use force in everyday life?
what is motion?
motion is the phenomenon in which an object changes its position over time. Motion is mathematically described in terms of displacement, distance, velocity, acceleration, speed, and time.
what is newtons 1st law of motion?
Newton's first law states that, if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force. This postulate is known as the law of inertia.
what is newtons 2nd law of motion?
Newton's second law of motion is F = ma, or force is equal to mass times acceleration. Learn how to use the formula to calculate acceleration.
what is newtons 3rd law of motion?
His third law states that for every action (force) in nature there is an equal and opposite reaction. In other words, if object A exerts a force on object B, then object B also exerts an equal and opposite force on object A. Notice that the forces are exerted on different objects.
What is the push or pull on an object that can cause it to accelerate called?
force
A change to an objects motion is caused by...
Unbalanced forces
Describe what happens if you are riding a skateboard and hit something (like a curb) with the front wheels
1 st Law Your body will keep moving forward and fly off your skateboard since the curb only stops the board, not yourself.
Using Newton’s laws explain why heavier objects require more force than lighter objects to move or accelerate them?
2 nd Law Something with more mass moving at the same acceleration as a lighter object would require more force to change its speed or change its direction. Our formula F=m x a is derived from Newton’s second law.
What happens according to Newton if you let an untied balloon go?
3 rd Law Air will rush out of the balloon forcing the balloon to move through the air in the opposite direction, but equal in force.
What is the unit of measure for force?
newtons
Projectile Motion is described as…
the curved path an object follows as it is thrown or propelled near earth’s surfaces
Explain how each of Newton’s laws affects a game of Tug of War
First Law: The rope will stay in the same place until the tugging starts (a new force is introduced)
A constant force of 30N acts on a a 10kg box as shown in the diagram. If the box is originally at rest, what will be its velocity after 5s?
−15ms
Two cars, one of mass 500kg and one of mass 250kg, collide head on. The car with more mass experiences a(n) __________ force and a(n) __________ acceleration with respect to the the smaller car.
equal . . . smaller
How much net force is required to accelerate a 2000 kg car at 3.00 m/s^2?
6000 n
The first law of motion says that an object at rest will remain at rest unless …
an outside force acts on it
A passenger in an elevator has a mass that exerts a force of 100N downwards. He experiences a normal force upwards from the elevator's floor of 120N. What direction is he accelerating in, if at all, and at what rate?
2 m/s^2 upwards
A 10kg box is being pushed across a frictionless field by two people. The box is moving with an acceleration of 1 m/s^2. What is the force applied by the weaker person, if the stronger person can push twice as hard?
10/3N
A book exerts a force of 2N downwards, into a chair that exerts a force of 5N dowwards to the floor it stands on. What is the force that the floor exerts upwards on the chair?
7N
The normal force acts on any object that:
touches a surface
According to the third law of motion, for every action there is …
an equal and opposite reaction
A box is sliding down a plane that has a inclination angle of θ=10∘. Calculate the coefficient of kinetic friction μk if the box is moving at a constant velocity v.
0.176
Is it possible to have a non-zero number of forces acting on an object (of non-zero mass), yet the object doesn't acclerate? yes or no ?
yes
A football player, feeling aggressive, is picking on a kid much smaller than himself. The football player asserts: "All of my hours in the weight room prove I can hit you harder than you hit me!" The smaller and more reserved gentleman replies: "Ya of course you can. I'm much weaker than you". Assuming by "hit" they mean "apply a force", are these two correct to think the football player can hit harder? Why?
No, Newton's third law says that the force two objects act on each other is always EQUAL in magnitude and opposite in direction.