What is the frequency of a wave having a period Equal to 18 seconds

How can you increase the intensity of sound waves

A sled starts atop a hill at rest with 3,000 J of potential energy relative to the bottom of the hill. When the sled reaches the bottom of the hill it has 2,000 J of kinetic energy.

Which of the following devices is made of two different metals and produces a voltage when the metals are exposed to heat? A. An accelerometer B. A photovoltaic cell C. A crystal D. A thermocouple

A ball (mass 0.40 kg) is initially moving to the left at 30 m/s. After hitting the wall, the ball is moving to the right at 20 m/s. What is the impulse of the net force on the ball during its collision with the wall? A) 20 kg.

An 8.0 cm diameter, 400 g sphere is released from rest ta the tip of a 2.1 m long, 25 degree incline. It rolls, without slipping, to the bottom.

Can a body be in equilibrium if it is in motion? Explain

What is the average speed in kilometers per second of the earth around the sun?

Why does a dog circle its bed before lying down

5. Which answer correctly summarizes the essential elements of a scientific theory?. A. descriptions of the natural world; based on many observations and data; do not explain why. B.

Light can travel through a medium, but it does not require a medium. a. True b. False