Physics 1 Flashcards
What does a vector tell us?
Give some examples
Product of 2 vectors, 1 vector and 1 scalar
Which ones are vectors?
A vector tells us the direction of magnitude of something.
Velocity, acceleration, distance, force, charge
Product of two vectors is not always a vector
Vector * Scaler = Always vector
Scalar: mass, temp, speed, work, energy, time, density
Vector: velocity, displacement, acceleration, force, weight, charge, e field, mag field, momutum, impulse, torque
What Is FORCE?
Example of ball being thrown
What does having 0 net force mean?
Anything that makes a given mass accelerate, even a change in direcction because acceleration is a vector
When a ball is being thrown it is only given force during the time it is in contact with our hand, then it is being given a constant gravitational force
0 net force means:
- No acceleration
- No change in velocity = constant velocity
- Object is in equibrilium
- Can still have cancelling forces
What is inertia and mass?
How do we calculate center of mass?
Inertia is the ability of an object to resist change in velocity.
Mass is the measure of interia
Center of mass= (Σrm)/total m
What does the slope of a displacement and time graph tell you?
What does the slope of the velocity and time graph tell you?
Slope= velocity, +ve= right of origin, -ve= left of origin
Slope = Acceleration, +ve= Moving right, -ve=Moving left (not necessarly past origin)
How do you calculate distance when start and finish velocities and time is known?
Distance=Avg vel*time
Avg Vel= v1+v2/2
Note: Used when things are going up
How to calculate Range ?
Range= Vx * time
Vx doesnt change over time, only force acting on it is gravity
X= (1/2) at2
V= at
V=sqrt(2gh)
T=2V/g
F= m a
How does air resistance change with the folloing :
cross section area, shape, velocity
What is the force at terminal velocity?
Inc area = Inc resistance
Less aerodynamic shape = Inc resistance
Inc velocity = Inc resistance
Fair = mg
How does gravity work?
What is the formula?
What is gravitational potential energy?
Anything moving down will accelerate at 10m/s, anything moving up will go to 0 velocity and then accelerate down at 10m/s
F= Gm1m2/r2
Potential energy = energy due to its position
PE= mgh
PE= -Gm1m2/r
What does friction oppose?
What are the kinds of friction and their formulas?
Friction opposes sliding NOT motion
Static: While NOT sliding, doesn’t have to be maxed out
Fs =ù N
Kinetic : While sliding, always max
Fk = ù N
N = mg CosØ
What the forces on an object on an inclined plane?
Fa = mg SinØ
Fn = mg CosØ
v = sqrt(2gh)
What do springs do?
What are the formulas for force and potential energy?
How do springs act together?
Springs act to restore the spring to its original position, x=0 which is its lowerst energy state
Fs =k delta(x)
PE = (1/2) k x2
2 springs side by side k = k1+ k2
2 springs in series 1/k = 1/k1 + 1/k2
Where does the motion start and end?
What are the two formulas for a spring and pendulum?
When the bob comes back to its original starting position
T = 2π sqrt(m/k)
T = 2π sqrt(l/g)
What is density and specific density?
What is the density of water?
Density is mass/volume
Density of water is 1000Kg/m3, 1g/cm3, 1g/ml
Specific Gravity = density of substance/density of water
What is buoyant force?
What is apparent weight and what does it tell us?
Fb = pvg
p = density of fluid displaced, v = volume of fluid displaced
Bouyant force is equal to the weight of the fluid displaced
Apparent weight = Actual Weight - Fb
Actual weight and Fb use same volumes, so comparing the two masses gives us the relative densities, which can be used for specific gravity problems
