Velocity

A boy and a girl are riding a merry-go-round which is turning at a constant rate. The boy is near the outer edge, while the girl is closer to the center. Which statements are true? (Give ALL correct answers: B, AC, BCD.., or None) A) The boy has the greater linear velocity B) Both have the same non-zero tangential acceleration C) Both have the same non-zero centripetal acceleration D) Both have the same period of circular motion E) Both have the same non-zero angular velocity

True and false questions about torque, a stick and a hanging mass. Question images in JPG format.

Shown below are six figures in which a student is holding a meter stick horizontally. In these figures, the length of the meter stick is denoted as L. All of the meter sticks are identical, but the objects hanging from the sticks vary in mass and position. The objects have masses of 500 g, 750 g or 1000 g as indicated in the figure below. Some of the masses hang from the end of the stick (distance L from the hand) and some hang at the midpoint of the stick (distance L/2 from the hand). In all cases, the student is keeping the meter stick from rotating downward by applying a torque at the end of the stick. The meter stick may be "harder" or "easier" to hold in different cases, dependin... click for more

Cube in water: density, volume and force calculations

Imagine that you have a solid cube composed of Material X. You put the cube into a beaker filled with water. The cube sinks to the bottom of the beaker and sits there, at rest, on the bottom. Which of the following statements are true? (Give ALL correct answers: B, AC, BCD, ... , or None) A) The buoyant force on the cube is less than its own weight B) The cube displaces an amount of water less than its own volume C) The cube of Material X weighs less than a cube of water the same size D) The normal force exerted by the bottom of the beaker on the cube is greater than the weight (in air) of the cube E) The substance must be more dense than water

Calculating the linear velocity of a clock hand.

The minute hand of a clock has a length of 6.0 cm. What is the linear velocity of the tip of the minute hand of this clock?

pressure under water

At the surface of a fresh water lake, you feel an absolute pressure that is equal to the normal atmospheric pressure (1 atm = 1.013à—105 Pa). How deep do you have to go in order to feel an absolute pressure of 5.1 atm?