Explain why a sewing needle can float on the surface a water in a glass

Sound wave travels through the air at 320 M/S and has a frequency of 150 HZ what is the wavelength of this wave

An ant on a picnic table travels 20 cm eastward then 25 cm northward 5 cm westward and finally 10 cm northward what is the ants displacement relative to its original position

A 2 kg ball rolls off a 27 m high cliff, and lands 25 m from the base of the cliff. Express the displacement and the gravitational force in terms of vectors and calculate the work done by the gravitational force.

An ideal solenoid having a coil density of 5000 turns per meter is 10 cm long and carries a current of 4.0 a. what is the strength of the magnetic field at its center?

Which could possibly be the pH of gastric acid?

A roller coaster car travels up and down the hills of its track. Neglecting friction, the sum of its kinetic and potential energy A. equals the sum of the thermal energy generated by friction during the ride. B.

In a transverse wave, if you increase of the wave you will get what kind of wavelength

What kind of system does not allow matter or energy to enter or exit? A. Connected B. Isolated C. Open D. Closed

Are the objects described here in static equilibrium, dynamic equilibrium, or not in equilibrium at all? a. A girder is lifted at constant speed by a crane. b. A girder is lowered by a crane. It is slowing down. c.

What kind of friction is shown between the skydiver and the air?