A power line carrying a sinusoidally varying current with frequency and peak value runs at a height of 7.0 across a farmer's land (see the figure). The farmer constructs a vertically oriented 2.0--high 15-turn rectangular wire coil below the power line. The farmer hopes to use the...

A 28.0 {\rm kg} child plays on a swing having support ropes that are 2.20 {\rm m} long. A friend pulls her back until the ropes are 45.0^\circ from the vertical and releases her from rest.

A(n) kg softball is pitched at a speed of m/s. The batter hits it back directly at the pitcher at a speed of m/s. The bat acts on the ball for s. What is the magnitude of the impulse

A uniform rod of mass 0.56 kg is 8 m long. The rod is pivoted about a horizontal, fric- tionless pin at the end of a thin extension (of negligible mass) a distance 8 m from the cen- ter of mass of the rod. Initially the rod makes an angle of 46 with the horizontal. The rod is released...

A constant torque of 28.0 N m is applied to a grindstone whose moment of inertia is 0.130 kg m2. Using energy principles, and neglecting friction, find the angular speed after the grindstone has made 15.0 revolutions.

An Alaskan rescue plane traveling 45 m/s drops a package of emergency rations from a height of 145 m to a stranded party of explorers. The acceleration of gravity is 9.8 m/s2 . Where does the package strike the ground relative to the point directly below where it was released?

If the crate has a mass of 110 kg and is 1.6 {\rm m} tall and 0.80 {\rm m} in depth and width, what is the minimum force needed to make the crate start tipping?

A 18 g rifle bullet traveling 250 m/s buries itself in a 3.6 kg pendulum hanging on a 2.8 m long string, which makes the pendulum swing upward in an arc. Determine the horizontal component of the pendulum's displacement.

A 42.0 kg child takes a ride on a Ferris wheel that rotates four times each minute and has a diameter of 18.0 m. What force does the seat exert on the child at the highest point of the ride?

The loaded cab of an elevator has a mass of 3.0 10^3 kg and moves 236 m up the shaft in 23 s at constant speed. At what average rate does the force from the cable do work on the cab? answer in kw