A-LEVEL PHYSICS: 11.1.9: Rotational Kinetic Energy (SaveMyExams)

Question 1

Ek = …

Answer 1

Ek = 1/2 mv^2

Question 2

kinetic energy (in terms of momentum) = …

Answer 2

Ek = p^2 / 2m

Question 3

rotational kinetic energy = …

Answer 3

R Ek = 1/2 Iω^2

Question 4

rotational kinetic energy (in terms of rotational momentum) = …

Answer 4

R Ek = L^2 / 2I

Question 5

circular objects, eg wheels, are made to move with both ___ & ___ motion.

Answer 5

linear, rotational

Question 6

rolling motion without slipping is a combination of ___ & ___ motion

Answer 6

rotating, sliding

Question 7

when a disc rotates: (2)

Answer 7

-each point on the disc has a different linear velocity (v) depending on its distance from the centre

-the v is the same at all points on the circumference

Question 8

when a disc slips/slides: (3)

Answer 8

-there is not enough friction present to allow the object to roll

-each point on the object has the same v

• ω=0

Question 9

when a disc rolls without slipping: (4)

Answer 9

-there is enough friction to enable rotation

-the point in contact with the surface has v=0

-the centre of mass v = ωr

-the top point has a velocity of 2v (or 2ωr)

Question 10

when an object rolls all the way down a slope, total kinetic energy = …

Answer 10

Ek total = 1/2 mv^2 + 1/2 Iω^2

Ek total = Eklinear + Ekrotational