Rotational Kinetic Energy and Angular Momentum

A disk with a large radius will always____in a race against a disk with a small radius.

• win
• lose 
• tie
• can't answer since it depends on the mass and radius of the disks!

A hoop rolls down a ramp from a height of h. Which expression below shows the speed of the hoop at the bottom? Which object will win the race?

• v=√(4/3)gh, disk
• v=√(4/3)gh, hoop
• v=√gh, disk
• v=√gh, hoop

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-4

The picture shown is an example of what physics principle?

• Conservation of Energy
• Conservation of angular momentum
• Conservation of Linear momentum
• Newton's Third Law

Tags

NGSS.MS-PS2-1

A solid disk and a hoop of the same mass and radius are released from the same point on an incline. The objects both move off the incline onto a table top and then move horizontally off the edge of the table. Which object will travel farthest from the edge of the table upon contacting the floor and is in the air the longest?

• The hoop will travel farthest and they will both be in the air the same amount of time
• The disk will travel farthest and they will both be in the air the same amount of time
• The hoop will travel farthest and be in the air the longest
• The disk will travel farthest and be in the air the longest

What are the metric units for the following quantities?
Angular distance
Rotational inertia
Rotational Kinetic Energy
Angular Momentum

• Radians
  J/s
  rpm
  Kgm/s
• degrees
  Kg
  Joules
  rad/s²
• Radians
  Kgm²
  Joules
  Kgm²/s
• Meters
  Kgm²
  Joules
  Kgm²/s

An ice skater performs a fast spin by pulling her outstretched arms down and close to her body. What happens to her angular momentum? 

• increases 
• decreases 
• stays the same

An experiment is performed in a physics class where three objects- a hoop, a cylinder and a solid sphere, roll down an incline of height, H without slipping. Which of the three objects reaches the bottom of their inclined planes first? 

• hoop
• cylinder
• solid sphere

Tags

NGSS.HS-PS2-1

A spinning skater draws in her outstretched arms and thereby reducing her moment of inertia by a factor of 2.  Determine how her rotational velocity changes. 

• It halves
• It is tripled
• It is doubled
• It is 1/3

A cylinder (I=¹/₂mr²) and a hoop (I=mr²) of the same radius and same mass are traveling at the same angular velocity (ω).  What is the ratio of the angular momentum of the cylinder to the angular momentum of the hoop?

• 1:1
• 1:2
• 2:1
• 1:4

A cylinder (I=¹/₂mr²) of mass M and radius r rolls with a linear velocity v.  What is its angular momentum?

• Mv
• Mv/r
• Mrv/2
• Mrv