Questions from College Physics

Q: A war-wolf, or trebuchet, is a device used

A war-wolf, or trebuchet, is a device used during the Middle Ages to throw rocks at castles and now sometimes used to fling pumpkins and pianos. A simple trebuchet is shown in Figure P8.89. Model it a...

Q: A string is wrapped around a uniform cylinder of mass M and

A string is wrapped around a uniform cylinder of mass M and radius R. The cylinder is released from rest with the string vertical and its top end tied to a fixed bar (Fig. P8.90). Show that (a) The te...

Q: The density of lead is greater than iron, and both metals

The density of lead is greater than iron, and both metals are denser than water. Is the buoyant force on a solid lead object (a) Greater than, (b) Equal to, or (c) Less than the buoyant force acting o...

Q: The Iron Cross When a gymnast weighing 750 N executes the iron

The Iron Cross When a gymnast weighing 750 N executes the iron cross as in Figure P8.91a, the primary muscles involved in supporting this position are the latissimus dorsi (“lats&aci...

Q: In an emergency situation, a person with a broken forearm ties

In an emergency situation, a person with a broken forearm ties a strap from his hand to clip on his shoulder as in Figure P8.92. His 1.60-kg forearm remains in a horizontal position and the strap make...

Q: An object of mass m1 = 4.00 kg is connected

An object of mass m1 = 4.00 kg is connected by a light cord to an object of mass m2 = 3.00 kg on a frictionless surface (Fig. P8.93). The pulley rotates about a frictionless axle and has a moment of i...

Q: A 10.0-kg monkey climbs a uniform ladder with

A 10.0-kg monkey climbs a uniform ladder with weight w = 1.20 x 102 N and length L = 3.00 m as shown in Figure P8.94. The ladder rests against the wall at an angle of θ = 60.0°...

Q: A 3.2-kg sphere is suspended by a cord

A 3.2-kg sphere is suspended by a cord that passes over a 1.8-kg pulley of radius 3.8 cm. The cord is attached to a spring whose force constant is k = 86 N/m as in Figure P8.95. Assume the pulley is a...

Q: A metal hoop lies on a horizontal table, free to rotate

A metal hoop lies on a horizontal table, free to rotate about a fixed vertical axis through its center while a constant tangential force applied to its edge exerts a torque of magnitude 1.25 x 10-2 N...

Q: A disk of mass m is spinning freely at 6.00

A disk of mass m is spinning freely at 6.00 rad/s when a second identical disk, initially not spinning, is dropped onto it so that their axes coincide. In a short time the two disks are corotating. (a...