NTN Mechanical Comprehension 3

Question 1

A spring-loaded rescue tool requires 80 pounds of force to compress the spring 4 inches. What is the spring constant (k)?

Accepted Answer

20 lb/in

Answer

40 lb/in

Answer

320 lb/in

Answer

10 lb/in

Question 2

A wheel and axle mechanism has a wheel diameter of 24 inches and an axle diameter of 4 inches. What is the mechanical advantage?

Accepted Answer

6:1

Answer

3:1

Answer

4:1

Answer

8:1

Question 3

A fire truck's water tank holds 500 gallons. If water weighs approximately 8.34 pounds per gallon, what is the approximate weight of the water when the tank is full?

Accepted Answer

4,170 pounds

Answer

3,170 pounds

Answer

5,170 pounds

Answer

2,170 pounds

Question 4

Two workers push a stalled vehicle. Worker A pushes with 150 pounds of force due east, and Worker B pushes with 200 pounds of force due north. What is the approximate magnitude of the resultant force?

Accepted Answer

250 pounds

Answer

350 pounds

Answer

175 pounds

Answer

50 pounds

Question 5

A belt-driven fan system has a motor pulley with a 6-inch diameter driving a fan pulley with an 18-inch diameter. If the motor runs at 1,800 RPM, what is the fan speed?

Accepted Answer

600 RPM

Answer

900 RPM

Answer

5,400 RPM

Answer

1,800 RPM

Question 6

A 10-foot ladder is leaning against a wall with its base 6 feet from the wall. How high up the wall does the ladder reach?

Accepted Answer

8 feet

Answer

4 feet

Answer

6 feet

Answer

10 feet