Forces Unit Flashcards
(24 cards)
What is a force?
A push or a pull
TOF: Forces always come in pairs
True
What unit is used to measure force?
Newtons
Balanced or unbalanced? A person standing still.
Balanced force
Balanced or unbalanced? A boy doing push-ups.
unbalanced force
Balanced or unbalanced? An object floating on water.
balanced force
Balanced or unbalanced? A fruit falling from a tree.
Unbalanced force.
Newtons 1st law.
Object at rest stays at rest…..Object in motion stays in motion.(unless outside forces)
Newtons 2nd law.
Force is equal to the mass multiplied by the acceleration. (heavier things take more force to have the same acceleration )
Newtons 3rd law.
All forces have an equal and opposite reactive force.
What is another name for Newton’s first law?
Inertia
What is another name for Newton’s 2nd law?
Acceleration
What is another name for Newton’s 3rd law?
Action-Reaction
What is inertia?
An objects desire to not move(if still) or to not stop moving(if moving)
How would inertia affect a driver when a car comes to a complete start?
The driver keeps moving when the car stops.
How would inertia affect a driver when a car immediately takes off from a resting position?
The driver remains still, so the seat has to push them forward.
Is it possible to push a 50 kg sled 5m/s/s with 100 newtons of force?
Force= ma No because 50 x 5 = 250 so you would need 250 newtons not 200.
Is it possible to move a 10 kg box 20 m/s/s with 500 newtons of force?
Force= ma Yes because 10x 20 = 200 so since 500 is over 200 newtons, that is more than enough.
What is gravity?
The force of attraction between objects with mass
What is the numerical value of gravity on Earth?
9.8 m/s/s
if a driver falls off a 10-meter board with no air resistance, what is his velocity at (a) 1 second (b) 2 seconds (c) 3 seconds?
(a) 10 m/s
(b) 20 m/s
(c) 30 m/s
If a canon is shot from ground level up at 100 m/s, what is the velocity after (a) 1 second (b) 5 seconds (c) 10 seconds
(a) 90 m/s
(b) 50 m/s
(c) 0 m/s
What is friction?
Rubbing force, or a force that slows down objects when in contact
Scenario: A shopping mall is having problems with shoppers slipping and falling when walking up the steps to get to the 2nd floor. What is the problem(physics perspective) and provide a realistic solution?
Too little friction, use grip tape or apply carpet if stairs are tile
