A. BANKER:
The formula for finding the balance in your account after it has earned simple interest for a given number of years is:
A= P + Prt
where A is the account balance
P is the amount of money you invested
r is the percentage rate your money earns
t is the amount of time in years that you left your money in the account
A1: How much should you invest in an account that pays 6% annual interest in order to have an account balance of $500 after 1 year?
A2: You need $396.80 to buy a stereo. You deposit $320 into a savings account with 12% interest. How long will it be before you have enough money to buy the stereo?
A3: You deposit $400 in a savings account. After one year, your balance is $428. What was your annual interest rate?
BONUS: To find compound interest, you use the formula:
A = P(1 + r) t
Again,
A is the account balance
P is the amount of money you invested
r is the percentage rate you are earning
t is the time in years that you leave your money in the account.
BONUS ??? You have a balance of $179.20 in your savings account 2 years after the account was opened. Your only transaction was the initial deposit. The annual interest rate is 6%. What was your initial deposit???
B. AUTO MECHANIC
The formula for finding the amount of horsepower produced by an engine whose pistons are turning a crankshaft is:
H = ( 1/136,000) PpArn
Where
H is the amount of horsepower
P is the average piston pressure in pounds per square inch
p is the piston stroke length in inches
A is the piston area in square inches
r is the crankshaft revolutions in RPM
n is the number of pistons
B1: An automobile engine is producing 150 horsepower with an RPM of 2500. The average piston pressure is 120 pounds per square inch, the piston stroke length is 3.3 inches, and the piston area is 10 square inches. How many pistons does the engine have?
B2: Your race car engine produces 667 horsepower with an RPM of 3000. The area of a piston is 9 square inches and the piston stroke length is 3.5 inches. There are 8 pistons in your car. What is the approximate piston pressure in pounds per square inch?
In rebuilding your engine, you must bore out a cylinder and replace the pistons. Before you bore out the cylinder, you must compute the volume of a piston. The volume of a cylinder is given by the formula:
V = π r2 h
where V is the Volume in cubic inches
π is 3.14
r is the radius of the cylinder
h is the height of the cylinder
B3: The volume of the cylinder must be 56.52 cubic inches. The cylinder’s length is 4.5 inches. What radius must your cylinder have?
C. CARPENTER:
The volume of a regular prism (like a box) is given by the formula:
V = L W H
where V is the volume in cubic units
L is the length of the prism
W is the width of the prism
H is the height of the prism
C1: You must make a wooden watering trough. The trough should hold 72 cubic feet of water. The side boards you are using are 12 feet long and 3 feet wide. How high must you make this trough??
The formula for the volume of a pyramid with a square base is
V = 1/3 h s2
where V is the volume in cubic inches
h is the height of the pyramid
s is the length of one side of the base of the pyramid
C2: The Great Pyramid in Egypt has a volume of about 90 million cubic feet and a square base with sides of about 750 feet. You must build a scaffolding to the top of the pyramid so that your company can do restoration work on this ancient monument. Use the formula to find the approximate height of the Great Pyramid so that you’ll know how high to build the scaffolding.
C3: In order to build a foot bridge and compute its weight limit, you must be able to figure out the amount of pressure exerted by a person. The formula for this is based on the width of the person’s heel and the weight of the person:
P = 1.2 w
H2
where P is the pressure
w is the weight in pounds
H is the width of the person’s heel
Joey’s shoes are 2 inches wide and Joey weighs about 150 pounds. How much pressure will he exert on the bridge?
D. METEOROLOGIST:
The formula for converting temperature in Fahrenheit into Celsius is:
F = 9/5 C + 32
where
F is the Fahrenheit temperature in degrees
C is the Celsius temperature in degrees
D1: Your Canadian reporting station says that the temperature there is 15 degrees Celsius. Change that to Fahrenheit so that you can report it to your U.S. audience.
D2: Your prediction for today’s temperature is 30 degrees Celsius. Should you wear a jacket? Why or why not?
D3: The Fahrenheit temperature today will be 63 degrees. Change that to degrees Celsius for your clients in Europe.
E. SCIENTIST:
Newton’s second law of motion explains how to compute the acceleration of a body.
The formula is:
F = ma
where
F is the force exerted
m is the mass of the object
a is the acceleration
E1: You are an astrophysicist and would like to determine the acceleration of an object you have observed in space. A force of 20 newtons is acting on a mass of 10 kilograms. (A newton is one kilogram-meter per second per second) What is the acceleration in meters per second per second?
E2: You are tracking a comet across a portion of the sky and you would like to find its rate. The formula to use is:
D = r t
where D is the distance traveled
r is the rate of the object
t is the amount of time
The comet you watch traveled 10,000 miles in 2 and a half hours. What is its speed in miles per hour?