What is the standard unit for TIME? (SI units)
seconds (sec, s)
What is the equation for VELOCITY?
velocity = displacement / time
If a problem says that an object starts from REST, what does that mean?
The initial velocity is equal to 0.
What is the velocity of an object with a displacement of -10 m and a total time of 10 seconds?
-10 m / 10 s = -1 m/s
What movie did we watch in class?
The Theory of Everything (movie about Stephen Hawking)
How many miles are there in 10,000 meters?
1609 meters = 1 mile
10,000 meters / 1609 meters= 6.22 meters
What is the equation for SPEED?
speed = distance / time
What is the velocity of an object at the TOP of its trajectory?
0 m/s
If an object has an acceleration of 15 m/s2 over a total time of 5 seconds, what is the average velocity of the object throughout its motion?
a = v/t
15 = v / 5
15 x 5 = v
75 m/s = v
What is the difference between distance and displacement?
distance is the TOTAL amount travelled. the displacement is how far an object is from the point of origin.
What are the units for displacement we use in this class?
meters (m)
What are the four kinematic equations?
If the acceleration of an object is changing, can we use the kinematic equations?
NO
Solve for the missing side of the triangle below.
angle 1 = 59 degrees
hypotenuse = 17
sin (59) = x / 17
17 x sin (59) = x
x = 14.57
Where does gravity always point? (Regardless of the planet of interest)
gravity always points DOWN towards the center of the planet.
If displacement is in miles and the time is in hours, what would the units for velocity AND acceleration be?
velocity - miles / hour
acceleration - miles / hour 2
A car is moving with a constant acceleration of 10 m/s2. If it starts from rest and travels for a total of 15 seconds, what EQUATION would I use to solve for the final velocity?
Vf = Vi + at
What is the OTHER BRANCH of mechanics aside from kinematics?
Dynamics
A tennis ball is thrown straight up with an initial speed of 22.5 m/s. It is caught at the same distance above grown. How high does the ball rise?
x = 26 m
List at least five (5) expectations I have for you in this class.
...
Convert 50 m/s to miles/hour.
1609 meters = 1 mile
60 seconds = 1 minute
60 minutes = 1 hour
111 mi/hr
What variable are each of the individual kinematic equations missing?
1. missing displacement
2. missing final velocity
3. missing time
4. missing acceleration
Explain why the units for acceleration are
displacement / time 2.
The units for acceleration are displacement / time2 because acceleration = velocity / time. Velocity has units of displacement / time. Therefore, acceleration is displacement / time / time which is
displacement / time2.
A construction worker accidently drops a brick from a high scaffold. What is the velocity of the brick after 4 seconds?
v = 39 m/s downwards
Describe the first lab we did in detail. What were we solving for? What did we do in Part A? Part B?
We measured the length of the table and for part A, found the amount of time it took the Car to span the length of the table. We then divided the length by the time to solve for the average velocity of the car.
For part B, we measured the distance between points on the table, and measured the time to get from point to point. We then found the velocity for each portion and averaged these.
We made a graph of position vs. time to also use the slope to find velocity.