what must be the distance between source of sound and mountain to give an echo in 5 seconds?, (speed of sound at 0°c=33m/sec

A boy pulls a wagon full of newspapers down the sidewalk at a constant acceleration. Suddenly, half the newspapers fall off the wagon. If the boy continues to pull with the same force as before, what happens? A. The net force remains constant. B.

As energy is added to a soild the atoms dash and move apart?

How many galaxies are there in the observable universe?

A 4.25-g bullet traveling horizontally with a velocity of magnitude 375 m/s is fired into a wooden block with mass 1.12 kg, initially at rest on a level frictionless surface.

Special relativity can be used to study an object in which frame of reference? A. A frame of reference that has no change in velocity B. A frame of reference that is moving in a circle C.

Block 1 and Block 2 have the same mass, m, and are released from the top of two inclined planes of the same height making 30 degree and 60 degree angles with the horizontal direction, respectively.

Water waves change direction when they encounter water of different depths and begin to move at different wave speeds. This is called A. reflection B. constructive interference C. the Doppler effect D. refraction

Along with an alpha particle what other product is produced in the alpha decay of americium-241

What does Newton's second law of motion say

Two sinusoidal waves are moving through a medium in the positive x-direction, both having amplitudes of 7.00 cm, a wave number of k=3.00m-1, an angular frequency of ω=2.50s-1, and a period of 6.00 s, but one has a phase shift of an angle ϕ=π12rad.