An experiment is conducted to determine how the arm length of a pendulum affects its period. the
experimental design calls for varying the length of the arm and the mass of the bob. which is true
about this experiment, based on good experimental design?
only the mass should be changed. the arm length should remain the same
the force applied to the mass should be varied for each trial
the material the arm is made of should be varied for each trial.
only the arm length should be changed. the mass should remain the same.

What would the difference of spectral lines emitted by hydrogen gas in distant galaxies which is normally found at a wavelength of 21 cm on earth, be observed at 21.1 centimeters?

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?

Pl asaaap ! match the term to the correct description. a type of wave that transfers energy where the particles in the medium move perpendicular to the direction in which the energy is traveling. a type of wave that transfers energy where the particles in the medium move parallel to the direction in which the energy is traveling. movement that is back and forth, like an equal sign = a type of wave that transfers energy where the particles in the medium move in a circle motion while the energy travels left or right. movement that is like a t transfers energy from one location to another 1. wave 2. parallel movement 3. perpendicular movement 4. transverse wave 5. longitudinal wave 6. surface wave