For a maximum, the amplitudes will add in phase when a.sin(theta) = lambda, if a is the slit-to-slit spacing. For a minimum, you have to figure out when 3 waves will add to zero. The intensity is proportional to the square of the sum of the amplitudes.
An electromagnetic wave has two components: electric (E) and magnetic (B). So the force on a charge is F = qE + qvxB. For a plane wave, E and B are perpendicular. Both oscillate at the frequency of the wave. The electric field will cause the charge to oscillate perpendicular to the wave...
Do this by taking the collision to happen on the horizontal surface (HS) -- the 7kg block must sit on the HS, the 2.2kg block slides down the incline on to the HS (not losing speed) collides with the 7kg block, then slides back up the incline. So do the problem in 3 steps: find the speed of the...
Force, mass, acceleration
To get the force, you need to know several things. Force acts on a mass to produce acceleration, according to N's 2nd Law: F=ma. So you'll need to know the mass of the baseball. Where does the force come from? Here, it is the pitcher who gets the ball up to speed...