As a fire truck approached Mary, the pitch of the siren got higher. once the fire truck passed and moved away, the sirens pitch got lower. this change in pitch is because in the sound waves

which of the following describes how the Earth's magnetic pole is related to its geographical poles? A. the magnetic poles and geographical poles are the same B. the magnetic poles vary depending on where on the Earth you are C.

A car goes from a velocity zero to a velocity of 15 meters per second East in 2.1 seconds. What is the car's acceleration?

Because the __ signal changes smoothly, like a sine wave, it can closely mimic a human voice. However, part of the signal can easily get lost to __.

One problem for humans living in outer space is that they are apparently weightless. One way around this problem is to design a space station that spins about its center at a constant rate.

A 30.0-kg girl in a swing is pushed to one side and held at rest by a horizontal force / vec{F} F ⃗ so that the swing ropes are 30.0^/circ30.0 ∘ with respect to the vertical.

1.) A circuit has a current of 0.5A and a resistence of 8 ohms. What is the resistence? 2.) A circuit has a voltage of 9V and a current of 3A, what is the resistence?

What is the source of energy for the process of evaporation?

How could you compare the energy carried in two different longitudinal waves

The instantaneous velocity of an object is the blank of the object with a blank

Which of the following best describes the earth's average surface temperature for the past 900,000 years? A. a steady warming trend B. fairly steady temperatures until recently C. prolonged periods of cooling and warming D.