PHYSICSMR. BALDWIN REVIEW10/4/13. Aim : What have we done so far? Let’s review. Do Now : Please take out your notebooks and make a list of what we have done so far? HOMEWORK: Prepare for TEST on Monday 10/7/13. A brief review sheet will be posted online.
Aim: What have we done so far? Let’s review.
Do Now: Please take out your notebooks and make a list of what we have done so far?
Prepare for TEST on Monday 10/7/13.
A brief review sheet will be posted online.
7 Basic Units of Measurement
In Physics, we will be working in the SI system, where the basic units are kilograms, meters, and seconds (m.k.s).
METRIC PREFIXES revised
These are the standard SI prefixes for indicating powers of 10.
Can you give any common everyday examples where these prefixes are used?
A car is moving at a speed of 90 km/h. What is the speed of the car in m/s? (Hint: Use Dimensional Analysis)
Order of Magnitude: Rapid Estimating
A quick way to estimate a calculated quantity is to round off all numbers to one significant figure and then calculate. Your result should at least be the right order of magnitude; this can be expressed by rounding it off to the nearest power of 10.
Calculate approximately how many basketballs (diameter = 75cm) can fit in this classroom randomly AND orderly stacked one atop the other?
Accuracy & Precision
Components of Vectors
If the components are perpendicular, they can be found using trigonometric functions.
Addition of Vectors: Resultant
For vectors in same or opposite direction, simple addition or subtraction are all that is needed.
You do need to be careful about the signs, as the figure indicates.
Uniform & Accelerated Motion
Average Speed & Instantaneous Speed
CHECK: Determine the units
Unit: m/s; km/h; mph
Acceleration is the change of velocity divided by time.
Where a: acceleration; vf: final velocity; vi:initial velocity
Determine its Unit.
Uniformly Accelerated Motion
Galileo’s Law of Freely Falling Bodies:
In the absence of air resistance, all objects, regardless of size, shape or mass, fall with the same acceleration.
Finding Speed: What can you say about the slope of the graph at any time?
The slope of the tangent to the distance-time graph at any point is the instantaneous speed at that point.
Speed-Time Graph of Uniformly Accelerated Motion
Slope gives acceleration of the body at each point.
Slope 2.00 m/s2
Graphical Analysis of Linear Motion
How would you find the area under the velocity-time graph?
The areabeneath the velocity-time graph gives you the Distance travelled