Tues 15 SEP:
Journal:
The acceleration of a falling object depends upon its mass. Why or why not!!!
1. Draw the following graphs:
· Position vs time:
a. For constant position
b. For constant velocity
c. For increasing velocity (at a constant rate)
· Velocity vs time:
a. For constant position
b. For constant velocity
c. For decreasing velocity at a constant rate
· Acceleration vs time
a. For constant position
b. For constant velocity
c. For increasing velocity at a constant rate
2. Formulas ( Quiz on Monday 20 Sep):
You must have these memorized!!!
Quiz (1st Equations) : (Monday 20 Sep)
1. (Relationship between work and energy)
W =
2. (net force – Newton’s 2nd law)
SF =
3. (Definition of acceleration- relationship with velocity)
a =
4. (Distance after a period of time)
Xf =
5. (Velocity after a period of time)
Vf=
6. (Velocity/distance/acceleration without time)
Vf2 =
7. (Mechanical Work)
W =
8. (Force of friction)
Ffrict =
9. (Kinetic Energy)
KE =
10. (Potential Energy)
DUg =
11. (Definition of Linear momentum)
r =
12. (Definition of change of momentum and Impulse)
Dr =
| 1. A ball is
dropped from an unknown height above the ground. When the object
is 11.0 m above the ground, it is observed to moving at 25.0
m/s. Neglecting air resistance, (A) How long will it take the ball to reach
the ground from 11.0 meters? |
|
(a) Ans: Vf 2 -Vo2 = 2aDx
Vf 2 -(-25m/s)2 = 2(-10m/s2)(11m)
Vf 2 = (-220) + (-625) = -845-2m/s --> -29m/s
Vf= Vo + at
-29m/s = (-25m/s) & (-10m/s2)t
--> t = 0.41s (for 11m final half)
(B) Ans (for top half): Vf = Vo + at
-25m/s = 0 + (-10m/s2)t
t = 2.5s
(for top half)
xt = V0t + 1/2at2
xt = 0 + (.5)(-10)(2.52) = -31.25
xt = -11 + -31.25 = - 42.25m
1) H/W Problems:
due Wed (16th)
#1
1. How far did the cart travel in the first 10 minutes? What was its average acceleration during this time interval?
2. Briefly describe its behavior between 10 and 15 minutes?
3. What was its average acceleration between 10 and 15 minutes?
4. How far did it travel between 15 and 30 minutes? What was its average acceleration during this time interval?
5. How far did it travel between 30 and 40 minutes? What was its average acceleration during this time interval?
6. How far did it travel between 40 and 55 minutes? What was its average acceleration during this time interval?
7. What was the total distance it traveled? What was its final displacement?
8.
What was the cart's average speed for the entire 55 minutes? its
average velocity?
- 300 meters, 6 m/min2
- it traveled 300 meters at a constant velocity of 60 m/min during these 5 minutes
- 0 m/min2
- 450 meters, -4 m/min2
- -200 meters, -4 m/min2
- -300 meters, 2.7 m/min2
- 1550 meters, +550 meters
- 28.2 m/min and 10.0 m/min
Pass out H/W
Name ____________________________ pd ____
Put in Scientific Notation:
1. .35 = _____________________
2. 13,500 = _____________________
3. .0006200 = _____________________
4. 2,400 x 102 = _____________________
5. 4,030,000 x 10-6 = _____________________
6. Solve to one significant figure (you don’t need a calculator):
(37,153 x 10 20 )(0.0096 x 10 -12) = _____________________
(167.6 x 10 -32)
Convert:
7. 156.6 km/hr to m/s = _____________________
show work:
8. 47 m3 to cm3 = _____________________
show work:
(9 & 10) Put into rectangular form (show diagram):
9. 52 ∟1500
X = ________ , y = ____________
10. 40 ∟323.10
X = ________ , y = ____________
11. Put resultant vector into rectangular then polar form (show diagram)::
x1 = 10, y1 = -7
x2 = -12, y2 = 23
x3 = -6, y3 = 2
x = ______ y = ________ à à __________ ∟_____0
12. Put into polar form (show diagram):
X = 90, y = 150 __________ ∟_____0
13. You bike east @ 20km/hr due for 30mins. Then head south @ 30km/hr for 1.0 hr. Then you head east again @ 20km/hr for 30mins. Finally, you head west at 40 km/hr for 2 hrs. (show diagram):
a. Speed
b. Displacement
c. Velocity