Physics Exam Flashcards
(17 cards)
Is acceleration a scalar or a vector?
Vector – it has magnitude and direction.
Define “scalar quantity.”
A quantity with magnitude only (e.g. speed, distance, mass).
What is the formula for average speed?
v= t/s
What is the unit of acceleration?
m/s^2
What’s the difference between speed and velocity?
Velocity includes direction, speed does not.
Convert 54 km/h to m/s.
3.6
54
=15m/s
What does
𝑠=𝑢𝑡+1/2𝑎𝑡^2
calculate?
Displacement, when initial velocity, acceleration, and time are known
what does the variables v,u,a,s stand for?
v = final velocity
u = initial velocity
a = acceleration
s = displacement
What does the slope of a velocity-time graph represent?
Acceleration
How do you calculate displacement from a velocity-time graph?
Area under the graph
A distance-time graph has a curved line. What does that mean?
The object is accelerating or decelerating.
State Newton’s First Law.
An object will stay at rest or move at a constant velocity unless acted upon by a net force.
State Newton’s Second Law.
F=ma; force is mass times acceleration.
State Newton’s Third Law.
For every action, there is an equal and opposite reaction.
How do airbags reduce injury?
They increase stopping time, reducing the force experienced by the body.
What’s the difference between mass and weight?
Mass: amount of matter (kg), doesn’t change.
Weight: force due to gravity (N), calculated as
W=mg.
What is net force?
The total force acting on an object after all forces are combined.
