An elevator descends into a mine shaft at rate of 15 metre per minute. a) What will be its position after 1 hour?
b) If it begins to descend 25m above ground, what will be its position after 45 minutes?

c)as speed changes, wavelength and frequency change.

everything changes!

the answer would be a

myth. it was once thought that animals, including cats and dogs, could only see in black and white. however, scientists have proven this to be a myth. in all animals, including humans, the perception of colour is determined by the presence of cells in the eye called cone photoreceptors.