What is the speed of a wave if the wavelength is 200 m and the period is 20 s?

The intensity of a polarized electromagnetic wave is 12 w/m^2. part a) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=0∘ with the plane of polarization? part b) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=30∘ with the plane of polarization? part c) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=45∘ with the plane of polarization? part d) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=60∘ with the plane of polarization? part e) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=90∘ with the plane of polarization?

In which of the following is positive work done by a person on a suitcase

Suppose a soccer ball is kicked from the ground at an angle 20.0º above the horizontal at 8.00 m/s. the y-velocity is determined to be 2.74 m/s. how long will the ball be in the air? assume the ball lands at the same height at which it was kicked.