Science Midterm Exam - Physics/Biology Flashcards
What is an equation’s use?
Equations are used to calculate quantities, using mathematical concepts
What is the equation for average speed?
Speed = distance/time
Define speed
How fast the position of an object moves over time (scalar quantity)
Why do we use “average speed”?
Most things do not travel at a consistent speed (unless they are on cruise control) so average is used
What is instantaneous speed?
How fast an object is travelling at a particular moment. ie - reading speed from a speedometer.
Is average speed and speed the same?
Yes
What units are speed measured in?
m/s (metres per second) or km/h (kilometers per hour)
If something is stationary, it is…
Stationary relative to us
What is a scalar quantity
Numerical value (eg. weight, speed, “70km/h”)
What is a vector quantity
Speed and direction (eg. “80km/h going North”)
How to get m/s to km/h?
x3.6
How to get km/h to m/s?
/3.6
What is velocity?
Speed with direction (eg. 5 km/h South)
What is the equation for velocity?
Same as speed (s=d/t)
What is the equation for distance?
Distance = speed x time
What is the equation for time?
Time = distance / speed
What is acceleration?
Increasing change in motion, increase in speed
What is deceleration?
Decreasing speed
Name types of relevant graphs
Distance/Time, Displacement/Time
(and speed/time but not as relevant)
In Distance/Time graph, what does a horizontal line mean?
Stationary
In a graph, what does a upward curve mean
Accelerating
In Distance/Time graph, what does a leveling curve mean
Slowing/stopping
In Distance/Time graph, what does a increasing line mean
Constant, fast speed
In a displacement/time graph, what does a horizontal line mean
Constant Speed
What is mass?
The quantity of matter in a given object
What can mass be measured by?
Kg, G
What is mass vs weight?
Weight is mass relative to gravity, mass is amount of matter in object
What are forces measured in?
N = Newtons
What are some examples of forces?
Gravity, thrust, friction, elastic tension
What is the acceleration due to gravity on Earth?
Approximately 10m/s/s
How many laws did Newton theorize?
3
What does an object’s inertia depend on?
Speed and Mass
What is the law of inertia?
A body at rest will remain at rest, and a body in motion will remain in motion unless an UNBALANCED force acts upon it
What is the law of acceleration?
An object travelling in a straight line will continue to do so unless acted upon by an unbalanced force
What is the law of interaction?
When two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction.
What impacts acceleration?
Size of force, mass of object
What quantity is acceleration measured in?
m/s/s (meters per second per second)
How do you calculate acceleration?
V - V0 (initial velocity) / time
What is energy measured in?
Joules = J
Examples of energy
elastic, kinetic, gravitational potential
What are the two categories of energy?
Kinetic, potential
Name examples of kinetic energy types
Heat, light, sound
Name examples of potential energy
Gravitational, elastic, chemical
What is energy transformation?
Energy goes from one energy type to another. EG: Kinetic to heat, gravitational potential to kinetic
What is energy transfer?
Energy is maintained but transferred/shifted from one object to another
EG: Punching a bag - kinetic energy transfer from fit to bag
What is EPgrav, and how is it calculated?
Gravitational potential energy:
Mass (kg) x Gravity (N) x Height (m)
What is EK, and how is it calculated?
Kinetic energy:
1/2 x Mass x Velocity²
How is EPgrav increased?
With increased height
How is EK increased?
With increased speed
How is EPelastic increased?
With increased bending, stretching, or compression
What is the Law of Conservation?
Energy cannot be created nor destroyed, only transformed or transferred.
How can energy transfer appear?
Through heat, light (sparks), and mechanical (collision). No energy is lost, just transformed.