Forces Flashcards
What force is acting on you when you are sitting on a stool?
Reaction Force
What force is acting on you as you brake on a bike?
Friction
What is the formula for Density?
Mass divided by Volume
What is the formula for Speed?
Distance divided by Time
What is the formula for Weight?
Mass X Gravity
A force can be a push, pull or …
Twist
What do you use to measure force?
A Newton Meter
What unit do you use to measure Force?
Newtons
What is air resistance also known as?
Drag
What is a balanced force?
Forces acting on an object that are the same size but act in opposite directions
What is Thrust?
A push caused by an engine
What are the two forces acting on a stationary rubber duck, sitting on a still lake?
Water Resistance and Weight
What are the two forces acting on a hot air balloon, traveling at a constant height?
Air Resistance and Lift
As well as Reaction Force and Weight, what two other forces are acting on a car, driving at a constant speed along a racetrack? (NOT COUNTING FRICTION)
Air Resistance and Thrust
Every 100g of mass weighs …
On earth
1N
Gravity is measured in …
N/kg
The earth’s gravity is…
9.8
If an object has balanced forces then it is either…
Stationary or traveling at a constant speed
What is Weight measured in?
Newtons
What is mass measured in?
Kilograms
What is friction?
A force caused by contact between surfaces that resists movement
What would be the two forces acting on a magnetic pen?
Magnetic force and Weight
When forces are unbalanced, an object will either…
Speed up or slow down
If you were pushing a box along the ground, apart from push and weight, what would the other two forces be? (NOT COUNTING FRICTION)
Air resistance and Reaction Force
What is Reaction Force?
The support force provided by a solid surface like a floor or tabletop
What is Speed measured in?
m/s (meters per second. Also can be kilometers per hour, miles per hour, etc)
How can you reduce friction?
Lubrication and Streamlining
What is elastic extension?
When an object changes shape and reverts back to the original shape
What is inelastic extension?
When an object changes shape and does not revert back to the original shape
Do rubber bands obey hooke’s law?
No
What is hooke’s law?
The extension of an elastic object is directly proportional to the force applied
What does directly proportional mean?
Where a line is straight and passes through the origin
What equation links the force applied to a spring and how far it extends?
F=ke
What does “k” mean?
Spring constant
What symbol does the spring constant have?
k
Name 3 non contact forces
Magnetic, electrostatic, weight
What is the difference between mass and weight?
Mass - amount of matter
Weight-amount of force acting on an object due to gravity
What do unbalanced forces do?
Make an object accelerate or decelerate
What is a force?
A force is a push, pull or twist acting on an object caused by interaction w/ another object
What can forces do?
Forces can make things change direction, speed or shape
What do you call a force diagram?
Free body diagrams
What is a vector quantity?
Something that has magnitude and direction
What type of quantity is force?
Vector
What are scalar quantities?
Things with only magnitude but no direction
What are some examplesr of scalar quantities?
Mass, speed, distance, time, temperature
What are some examplesr of vector quantities?
Force, velocity, displacement, acceleration, momentum,
What happens when two objects interact?
There is a force produced on both objects
What is an interaction pair?
A pair of forces that are equal and opposite and act on two interacting objects
Is mass a force?
NO
Is weight a force?
YES
delete this
Name two things that are directly proportional
Mass+weight,extension and force applied (spring)
Will you weigh more on the earth or the moon?
Earth
1N is equivalent to how many grams?
1kg
If something has a mass of 55kg, what is its weight?
539 (multiply by 9.8)
What does the spring constant tell us about a spring?
the stiffness
What is the unit of the spring constant?
N/m
What is the formula for force applied on a spring?
f=ke
Which force acts upwards on a boat sitting in water?
Upthrust
what is the unit of gravitational field strength?
N/Kg
Which equation links density, mass and volume?
density = mass / volume