Questions from Modern Physics

Q: A non-uniform beam 4.50 m long and weighing

A non-uniform beam 4.50 m long and weighing 1.40 kN makes an angle of 25.0° below the horizontal. It is held in position by a frictionless pivot at its upper right end and by a cable 3.00 m...

Q: Two forces equal in magnitude and opposite in direction, acting on

Two forces equal in magnitude and opposite in direction, acting on an object at two different points, form what is called a couple. Two antiparallel forces with equal magnitudes F1 = F2 = 8.00 N are a...

Q: You are doing exercises on a Nautilus machine in a gym to

You are doing exercises on a Nautilus machine in a gym to strengthen your deltoid (shoulder) muscles. Your arms are raised vertically and can pivot around the shoulder joint, and you grasp the cable o...

Q: A student bends her head at 40.0° from the

A student bends her head at 40.0° from the vertical while intently reading her physics book, pivoting the head around the upper vertebra (point P in Fig. E11.23). Her head has a mass of 4.5...

Q: The work done by a force is the product of force and

The work done by a force is the product of force and distance. The torque due to a force is the product of force and distance. Does this mean that torque and work are equivalent? Explain.

Q: A relaxed biceps muscle requires a force of 25.0 N

A relaxed biceps muscle requires a force of 25.0 N for an elongation of 3.0 cm; the same muscle under maximum tension requires a force of 500 N for the same elongation. Find Young’s modulus for the mu...

Q: A circular steel wire 2.00 m long must stretch no

A circular steel wire 2.00 m long must stretch no more than 0.25 cm when a tensile force of 700 N is applied to each end of the wire. What minimum diameter is required for the wire?

Q: Two circular rods, one steel and the other copper, are

Two circular rods, one steel and the other copper, are joined end to end. Each rod is 0.750 m long and 1.50 cm in diameter. The combination is subjected to a tensile force with magnitude 4000 N. For e...

Q: A metal rod that is 4.00 m long and 0

A metal rod that is 4.00 m long and 0.50 cm2 in cross sectional area is found to stretch 0.20 cm under a tension of 5000 N. What is Young’s modulus for this metal?

Q: A nylon rope used by mountaineers elongates 1.10 m under

A nylon rope used by mountaineers elongates 1.10 m under the weight of a 65.0-kg climber. If the rope is 45.0 m in length and 7.0 mm in diameter, what is Young’s modulus for nylon?