Engineering (mechanics)

Question 1

-what is moment of inertia?
-what is the equation?

Answer 1

-a measure of an objects resistance to being rotationally accelerated about an axis

I=mr²

Question 2

what does moment of inertia depend on?

Answer 2

• the objects’ total mass
• how it’s mass is distributed about the axis of rotation

Question 3

what feature does a flywheel have that makes it useful for it’s purpose?

Answer 3

has a large moment of inertia, therefore when rotationally accelerated , it is difficult to stop, and the input torque that causes it to spin is converted into rotational kinetic energy

Question 4

what are the factors which affect how much energy a flywheel can store?

Answer 4

• mass of flywheel
• angular speed of the flywheel
• friction
• spokes

Question 5

what are the uses of flywheels?

Answer 5

• regenerative braking in vehicles
• wind turbines
• smoothing torque and angular velocity

Question 6

what is torque?
equation?

Answer 6

the product of a force and its distance from the axis of rotation

T= Fr

Question 7

what is angular momentum?

Answer 7

the product of the moment of inertia and angular velocity of an object

Question 8

what is the law of angular momentum?

Answer 8

the angular momentum of a system remains constant unless acted upon by a external torque

Question 9

what is angular impulse?

Answer 9

the product of torque and its duration

Question 10

how can you calculate frictional torque on a wheel experimentally?

Answer 10

1. apply an accelerating torque on a wheel to bring it up to a certain velocity
2. remove the accelerating torque, and measure the time taken for the wheel to come to rest
3. calculate the average deceleration using the equation
4. calculate frictional torque using the equation T= Iα