Physics - Rotational K.E. - Requiz

Because a hollow ball has a higher moment of inertia than a solid ball...

• The solid ball accelerates faster

• The solid ball weighs more.

• The solid ball weighs less.

• They both accelerate at the same rate.

If a ball moves with slipping down a ramp

• it goes slower than if it had rolled down
• it moves faster than if it had rolled down.
• It doesn't make a difference about friction or not friction.
• Friction slows it down.

Tags

NGSS.HS-PS2-1

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 rotational kinetic energy of the cylinder to the rotational kinetic energy of the hoop?

• 1:1
• 1:2
• 2:1
• 1:4

What is the kinetic energy of a 3 kg solid disk (I = 1/2mr²) with a diameter of 80 cm rolling at 4 m/s?

• 12 J

• 24 J

• 36 J

• 48 J

You roll a solid sphere of mass m and radius r (I = 2/5mr²) down a ramp from a height of h, if it starts at rest what is its linear speed at the bottom?

• √(1.4gh)

• √(2gh)

• √(3.5gh)

• √(5gh)

The figure shows scale drawings of four objects, each of the same mass and uniform thickness, with the mass distributed uniformly. Which one has the greatest moment of inertia when rotated about an axis perpendicular to the plane of the drawing at point P?

• A
• B
• C
• D

Three homogeneous ridged bodies -- a solid shere, a solid cylinder, and a hollow cylinder -- are placed at the top of an incline.  If all are released from rest at the same elevation and rolls without slipping, which reaches the bottom first?

• The solid sphere.
• The solid cylinder.
• The hollow cylinder.
• They will all arrive at the same time.

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

At what angle should the force be applied to a wrench to produce the maximum torque?

• 0⁰ to the handle

• 90⁰ to the handle

• 180⁰ to the handle

• 360⁰ to the handle

The four particles in the figure are connected by rigid rods of negligible mass. The origin is at the center of the rectangle. If the system rotates in the xy-plane about the z-axis with an angular speed of 6.00 rad/s. Calculate the moment of inertia of the system about the z-axis.

• 143 kg⋅m²

• 71.5 kg⋅m²

• 286 kg⋅m²

• 107.2 kg⋅m²

The four particles in the figure are connected by rigid rods of negligible mass. The origin is at the center of the rectangle. If the system rotates in the xy-plane about the z-axis with an angular speed of 6.00 rad/s. Calculate the rotational kinetic energy of the system.

• 2.57 kJ

• 1.29 kJ

• 5.14 kJ

• 1.93 kJ