Aprojectile is fired straight upward at 173 m/s. how fast is it moving at the instant it reaches the top of its trajectory?

An object has a weight of 500 on earth what is the mass of this object

What is a good example of instantaneous speed

Light from a sodium lamp passes through a diffraction grating that has 1000 slits per millimeter. the interference pattern is viewed on a screen 1.000 m behind the grating. the first (m = 1) two bright yellow fringes that are visible are 0.7288 m and 0.7300 m from the central maximum. what are the wavelengths of these two fringes?