A glass rod rubbed with silk acquires ………….. charge.

What do you think car designers do if the damage caused by a crash test is too severe?

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?

Acertain radio station broadcasts radio waves that have a wavelength of 298cm what is its broadcast frequency?