Linangan Physics Day 10

Will a child standing at the rim of a merry-go-round revolving with a constant angular velocity have any tangential acceleration?

• Yes

• No

The figure shows the top and side-views of two centrifuge designs of the same masses and radii, and with the the same number of same sized test tubes. If both of their masses and radii are doubled while maintaining the design, their rotational inertias will increase by what factor?

• 2

• 4

• 8

• Cannot be determined

A solid sphere is rotating in free space. If the radius of sphere is increased while keeping the mass same, which one of the following will not be affected?

• Moment of inertia

• Angular momentum

• Angular velocity

• Rotational kinetic energy

Figure A below shows a meter stick, half wood and half steel, that is pivoted at the wood end at O and a force applied at a. In figure B, the stick is reversed and pivoted at the steel end at O’, and the same force is applied at the wood end at a’. The resulting angular acceleration of figure A is _ figure B?

• Greater than

• Less than

• Equal to that of

The figure shows the top and side-views of two centrifuge designs of the same masses and radii, and with the the same number of same sized test tubes. Which of the two centrifuges has greater rotational inertia?

• A

• B

• The same

• Cannot be determined

The figure shows an overhead view of a meter stick that can pivot about the point indicated, which is to the left of the stick’s midpoint. Two horizontal forces are applied to the stick. Only one of them is shown, the other is perpendicular to the stick and is applied at the right end. If it were to not move,

• The force on the right side must go upwards.

• The force on the right side must go downwards.

• The force of the right must be of greater magnitude than the one on the left

• The force of the right must be of lesser magnitude than the one on the left

The Sun subtends an angle of about 0.5° to us on Earth, 150 million km away. Estimate the radius of the Sun in kilometers. Express in 3 significant figures.

Mathematical Equivalence

ON

What is the angular momentum of a 0.270-kg ball revolving on the end of a thin string in a circle of radius 1.35 m at an angular speed of 10.4 rad/s? Give your answer in 3 significant figures and in SI units.

Mathematical Equivalence

ON

A bowling ball of mass 7.25 kg and radius 10.8 cm rolls without slipping down a lane at 3.10 m/s. Calculate its total kinetic energy. You may look up the formular for the moment of inertia of a sphere. Give your answer in 3 significant figures and in SI units.

Mathematical Equivalence

ON

Calculate the net torque about the axle of the wheel shown in the figure. Assume that a friction torque of 0.6 Nm opposes the motion. Give your answer in 2 significant figures and in SI units.

Mathematical Equivalence

ON