Monday & Tuesday, November 24-25,2008

Today I'll be doing two blogs since I forgot to do it for monday and assign someone for Tuesday. First we corrected alot of sheets in physics, "Components of vectors", first page of Acceleration, 4.1 What is acceleration?

Components of vectors

1. b
2. b
3. c
4. b
5. d
6. a
7. c
8. c
9. b
10. c
11. c
12. c
13. c
14. c

Acceleration (first page)

1. a = V2-V1/Change of time = 25m/s-0m/s / 4s-0s = 6.3 m/s²
2. a = V2-V1/change of time = 29.28m/s-0m/s / 3s-0s = 9.8 m/s²
3. V2 = V1 + a(change of time) = 28m/s + (2.5m/s²)(3s-0s) = 36m/s
4. change of time = V2-V1 / a = 14.1m/s -0m/s / 13.2m/s² = 4.4s
5. change of velocity = a(change of time) = 56.3m/s²(1.9) = 107m/s = 110m/s with sig. digits

What is Acceleration?

The change in velocity divided by the time interval is average acceleration. It can be calculated using the equation a=v/t. In this equation a stands for acceleration, ٨V stands for change in velocity, and ٨t stands forthe time interval. If velocity is measured in metres per second, acceleration is measures in m/s/s, which is read as metres per second per second. The unit also can be written as m/s², which is read as metres per second squared. Like velocity, acceleration is a(n) vector quantity, which means it has both magnitude and direction. When velocity increases, acceleration is positive. When velocity decreases, acceleratin is negative.

Average and Instantaneous Acceleration

A velocity-time graph shows how velocity depends on time. The rise of the curve represents the change in velocity. The run of the curve represents the time interval. The slope of the curve represents the average acceleration. If the curve on a velocity-time graph is a straight line, the acceleration is constant. If the curve is not a straight line, acceleration is changing. The slope of a line tangeant to the curve is the instantaneous acceleration at that time.

Velocity of an object with constant acceleration

Acceleration that does not change in time is constant, or uniform, acceleration. The velocity when the clock time is zero is the initial velocity. The velocity after acceleration has occurred is called the final velocity, and is calculated using the equation V2=V1+at. In this equation, V2 is final velocity, V1 initial velocity, a is acceleration, and t is time interval.

Displacement when velocity and time are known

If an object is accelrating, its displacement can be calculated using the equation d=(V2+V1/2)t. In this equation, d stands for displacement, V2 stands for final velocity, V1 stands for initial velocity, and ٨t stands for time interval. To find displacement using a velocity-time graph, find the area under the curve.


Well this is all i can remember correcting over these two days, tell me if i forgot something and i'll try to find the answers to those also. Also don't forget to do the 2nd page on "Acceleration" as we will probably correct it in class tomorrow.

TOMORROW'S SCRIBE : Suzette