What is the velocity of an object that has been in free fall for 1.5s?
a. 150 m/s downward
b. 6.5 m/s downward
c. -6.5 m/s downward
d. 15 m/s downward

What is hidden during a lunar eclipse? isn't the moon hidden?

One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?

Afrequency generator sends a 550 hz sound wave through both water and ice. what is the difference in wavelength between the wave produced in ice and the wave produced in water?