### AP Physics 1 Week 7 (July 23 - 29, 2017)

Part 1:  Algebra (Rearrange)

1.  solve for   l

2. solve for x

3. solve for v

4. solve for VR

5. solve for q

Part 2:  Algebra (Inverse and Direct Relationships)

6.  The rate of flow of water emerging from the end of a circular pipe under a fixed pressure is directly proportional to the square of the radius of the pipe.  If a pipe of two inch radius emits 864 cubic inches of water per second, at what rate will a pipe of 2.25 inches radius emit water under the same pressure?  (DBW, p224, #6)

7.  The power required to drive a nautical vessel varies directly as the cube of its speed.  If 450 horsepower are needed to run the Bombay Queen at 6 knots, what horsepower is required to drive her at 8 knots?  (DBW, p224, #7)

8.   The maximum deflection of a beam is directly proportional to the cube of its length.  If a maximum deflection of 0.002 centimeters occurs in a beam 10 meters long, find the deflection in a 6 meter beam.  (DBW, p224, #8)

9.  A square plate 3 inches wide has a moment of intertia of 6.75.  What is the moment of inertia of a square plate 2 inches wide, if the moment of inertia varies directly as the fourth power of the width of the plate?  (DBW, p224, #9)

10.  The crushing load of a circular pillar with a 10 inch diameter is 200 tons.  Find the crushing load of a pillar of the same height and material but with a diameter of 14 inches, if the rushing load is directly proportional to the fourth power of the diameter.

(DBW, p224, #10)

Part 3: Geometry/Trigonometry
(For Physics, make sure your calculator is set in degrees)

Pythagorean Theorem (math version) c2 = a2 + b2, (physics version) r2 = x2 + y2
r = hypotenuse of the right triangle
x = horizontal or (east-west) component of the triangle
y = vertical or (north-south) component of the triangle
q = the reference angle (theta) always between the x axis and the hypotenuse

horizontal component x = r*cos(q)  vertical component y = r*sin(q)

11.  Jerry walks 1 block (217 feet) east along a vacant lot and then 2 blocks (400 feet) north to a friends house.  Pam starts at the same point and walks diagonally through the vacant lot coming out at the same point as Jerry.  How far did Pam walk?
(DBW, p 393, #1)

12.  In a naval maneuver two ships rendezvous at position A.  One then proceeds east 10 miles and north 14 miles to position B.  At what bearing or direction (angle) should the second ship head to meet the first ship at position B? (DBW, p 394, #3)

13.  A jet heads due west at 627 miles per hour.  If a 25 mile per hour north wind is blowing, what is the planes ground speed and course (direction)?  (DBW, p 394, #4)

14.  At what bearing or direction (angle) and speed would a pilot head if he wants to fly due north at 345 miles per hour when a 40 mile per hour west wind is blowing?
(DBW, p 394, #5)

15.  At what bearing and speed should the navigator direct the captain of a ship to head, if the captain wants to steam straight ahead at 18.2 knots when seas of 7.4 knots are hitting the ship broadside?  (DBW, p 394, #6)

Part 4:  Word Problems

16.  Tonya's outboard can drive her boat at 7 mph in still water.  It takes her 10 minutes

more to reach her friends camp 4 miles up the river that to return to her camp

down river.  What is the speed of the current? (DBW, p201, 39)

17.  Jack was standing on a direct line between Tom and the point on the surface of the             earth where a bolt of lightning struck.  If Tom heard the sound of the thunder

associated with the lightning 5.5 seconds after it struck, how far was he standing

from Jack if Jack was standing 4480 feet from the point where the bolt struck.

Jack heard the thunder 1.5 seconds before Tom.  (DBW, p217, #13)

18.  At noon a ship sailed east from Key West.  Two hours later another ship traveling

4 mph faster sailed due south from that port.  At 10 pm the same (Key West

time), the ships were 100 miles apart.  What was the average speed of each?

(DBW, p296, #9)

19.  Park City is 23 miles directly south of Adobe Flats.  A train running due west at 40

mph left Park City at the same time another train traveling due south at the same             speed left Adobe Flats.  How soon were the trains 17 miles apart?

(DBW, p297, #10)

20.  When a favorable wind caused an increase of 20 mph over the usual speed of the

plane, the pilot made the 980 mile trip between 2 cities in 7 minutes less time.

Find the usual speed of the plane. (DBW, p326, #8)