Astone was dropped off a cliff and hit the ground with a speed of 88 ft/s . what is the height of the cliff? (use 32 ft/s 2 for the acceleration due to gravity.)

What are atoms of the same element with varying number of neutrons

Alinearly polarized electromagnetic wave has an average intensity of 196 w/m^2. this wave is directed towards two ideal polarizers (in real polarizers, transmission is also effected by reflection and absorption). polarizer a is oriented with its transmission axis at an angle of θ_1=20.8∘ with the incident electric field. polarizer b has its axis at an angle of θ_2=63.0∘ with the incident electric field. what is the average intensity of the wave after it passes through polarizer a? what is the average intensity of the wave after it passes through polarizer b? suppose that the two polarizers a and b are interchanged. what would the average intensity be after passing through both polarizers?

Could we see a galaxy that is 20 billion light-years away?