Robtics 1 Final Exam Full

1.\_________ are used to protect your eyes.

safety glasses

A \_________ is commonly used to reduce the friction of rotating parts in a machine.

bearing

A \__________ is a device used to connect the transmitter directly to the Vex controller.

tether

A 1/4-20 x 0.50" screw has how many threads per inch?

20

A Servo Module can rotate \_________.

continuously

A Vex motor is:

a device that converts electrical energy into mechanical energy

How many joysticks control the robot's drive train in Arcade control?

one

How many joysticks control the robot's drive train in Tank control?

Two

. How many programs can be stored in the Vex controller's memory?

one

If an injury occurs in the classroom, what is the first thing you should do?

report it to your teacher

11 If two gears are set up with a center-to-center distance that is too long they will \________.

mesh loosely or not mesh at all

If you are missing a component from your kit, you should \__________.

report it to your teacher

Moving the right joystick up in the vertical direction while in Arcade control \__________.

moves both left and right side of the robot forward

Never wear \_______ in the shop area.

sandals

Reduced power and response time of the motors is an early indicator of:

low battery

Select the answer that best describes "center of gravity":

a measure of robot stability

The \________ is the brain of the robot.

controller

The \__________ code inside the Vex controller allows you to configure and operate the Vex robot without having to program the robot.

default

The \__________ step of the engineering design cycle allows designers to be creative and think outside of the box.

brainstorming

The \____________ signal from the robot controller instructs the robot to do something.

output

To protect yourself and others from harm in the classroom you should:

keep your work area clean and orderly

Transmitter signals radiate from the \__________.

tip of the transmitter antenna

Vex jumper clip is used to \__________.

close two open points in a circuit on the controller

What are the two signals that make up an FM radio wave?

carrier signal and information signal

What color is the connector on a Motor Module?

blue

What is voltage drop?

a decline in the amount of current stored in a battery

Which description below best characterizes a bolt?

a fastener with external threads specified to match a nut

Which of the following is not a component of a robotic system?

program

Which of the following is not a main attribute of a screw:

color

Which of the following is not a step of the engineering design cycle?

iteration

Which of the following is not a subsystem of the BaseBot?

wheel

Which of the following is not an engineering notebook requirement?

perforated paper for easy removal

Why is it important to organize all the inventory of robotic components?

to easily locate the robotic components needed for assembly

You should never operate a Vex motor without a \_______.

clutch

Your robot uses the standard called:

802.11g

1. "CW" is an abbreviation for:

clockwise

2. A "char" variable type is 8 bits. This means:

it can hold 256 possible values

3. A "signed" variable type is one that:

can hold either positive or negative number values

4. A "syntax" error is when:

a program error prevents compilation

5. A for() loop is used to:

execute a section of code a certain number of times

6. A PWM value of 0 will cause a Motor Module to:

stop moving

7. A PWM value of 127 will cause a Motor Module to:

turn full speed CCW

8. A while() loop is used to:

execute a section of code until a condition is met

9. An autonomous robot is one that:

uses its own intelligence or program to handle different situations

10. An if-else statement is used when:

you need to do one thing or the other but not both

11. Assuming "headcount" is a variable of type unsigned char, and its current value is 175, what is the most you can add to it before it starts to wrap?

80

12. Assuming that "final" is an int variable, what is the value of "final" after the following code fragment? final \= 17; final /\= 3;
5

5

13. It is valid to nest a "while()" statement inside a "for()" loop:

always

14. Signed ints versus unsigned ints:

wrap at a lower value

15. The '\==' symbol is used to:

perform a comparison with no assignment

16. The "Begin" and "End" blocks are in your program to:

encapsulate your code between starting and ending points

17. You have a bin full of good tires ("tires"), and you need to know how many will be left over ("leftovers") after you take out all the full sets of 4. The code would look like:

leftover \= tires % 4

18. The Wait() command will cause your program to:

pause for a certain number of milliseconds

19. When you compile your program, you are:

converting your C program machine language

1. A 10-tooth driver gear meshes with a 20-tooth idler gear, which in turn, meshes with a 40-tooth driven gear. What is the gear ratio of the gear train?

1 to 4

2. A 12 tooth gear is driven by a 36 tooth gear attached to a motor that produces 90 oz·in of torque. How much torque will be provided to the wheels?

30 oz·in

3. A 2.0 kg robot will weigh how many pounds?

4.4 lbs.

4. A 5 inch wheel rolls 5 revolutions on a horizontal surface without slipping. How far did the wheel travel?

78.5 inches

5. A 5 lb force acting on a 5 inch wheel will produce a torque of:

200 oz·in

6. A 60 tooth gear is driven by a 12 tooth gear attached to a motor that produces 80 oz·in of torque. How much torque will be provided to the wheels?

400 oz·in

7. A force of 25 lbs acting on a 6 in. wrench yields a torque of:

12.5 ft·lbs

8. A motor works because of thousands of wire loops called:

windings

9. A robot has wheels with a 2.75 inch radius spinning at 100 RPM. How fast can it go?

14.4 ft/s

10. A robot has wheels with a 3 inch radius spinning at 100 RPM. How fast can it go?

2.6 ft/s

11. A torque of 99 ounce·inches acting on a 6 in. wheel produces a force of:

2.1 lbs

12. Acceleration is defined as the change in:

velocity divided by the time it took.

13. Accelerations are produced by:

forces

14. An electric motor is useful because it turns electricity into:

mechanical energy.

15. Cars and robots are not limited by the amount of energy they use, but by the rate at which they use the energy. This is an example of limitation by what?

Power

16. Find the work done when a block is moved a distance of 3 ft. by a force of 15 lbs.

45 lb-ft

17. Friction is a force that always acts\____.

opposed to the object's motion

18. How can you increase the torque supplied by the Vex motors?

Change the gear ratio

19. How much does robot weigh if its mass is 0.125 slug?

4 lbs.

20. If the BaseBot travels 15 ft. in 6.7 seconds, what is the average speed?

2.2ft/s

21. In order for the Basebot to roll up a 10° slope it must exert a force that is at the very least equal the forces that work against it. If the forces acting downhill total 2.5 lbs, how much power is produced if the robot travels uphill at 1 ft/s?

2.50 lbs-ft/s

22. Newton's 2nd Law says:

force equals the product of the mass and acceleration

On a gear, the fulcrum is:

the center of the gear

24. Rubber on floor tile has a coefficient of kinetic friction of 1.0 and a coefficient of static friction of 2.0. How much force would a 3.5 lb. robot need to produce in order to start moving?

7.0 lbs.

25. The Basebot is propelled forward when the wheels:

roll

26. The BaseBot starts at rest and accelerates to a speed of 1.6 ft/s in 2.3 seconds. What was the acceleration of the BaseBot?

8.3 in/s2

27. The kinetic friction of one object sliding along a surface depends LEAST upon:

the area of contact

The motors on the robot act with a 5 lb. force to move the robot and friction acts with 1 lb. force. What is the net force acting on the robot?

4 lbs

33. The motors used in the VEX robotics kit are:

hobby servos

34. The part of the motor that turns is typically called the:

rotor

35. The strength of a battery's charge is measured in:

volts

36. Torque acting on an object produces:

rotation

37. Torque is:

force times moment arm length

38. Velocity can be defined as:

displacement traveled divided by the time it took

39. What amount of force is necessary to move a robot that weighs 4 lbs. at an acceleration of 12 ft/s^2?

1.5 lbs

40. What is the wheel rollout of a 6 inch wheel in feet?

1.57 ft

41. When using gear trains in a robot, trade-offs must be made. If the robot needs to increase torque, there will be a proportional trade-off in what?

speed

42. Which of the following formulas will NOT determine the gear ratio of a gear train?

the pitch in the driven gear divided by the pitch in the driver gear

43. Which of the following is a gear head motor?

modified hobby servo

44. Which of the following is a rechargeable wet cell battery?

lead acid

45. Which of the following is not a dry cell battery?

lead acid

46. Which of the following is NOT a unit of measure for angular velocity:

m/s

47. Which parameter is important when two different diameter gears need to mesh properly?

pitch

48. Which type of gears does the Vex robotics kit contain?

spur

49. Why is it more difficult for a robot to start moving than it is to keep moving after it is in motion?

the coefficient of static friction is greater than the coefficient of kinetic friction

50. Work is done when an object is moved a certain distance by which of the following?

force