Acrew team rows a boat at a rate of 20 km/h in still water. in practice on a river, the team rows for 30 minutes up the river (against the current), and then for 30 minutes down the river (with the current). the speed of the river current is 1.5 km/h. how much farther did they travel in the second 30 minutes?

Astudent is given an assignment to demonstrate diffraction. he takes a photograph of a straw in a glass of water. the straw appears bent at the water level. which best describes this example? a) this is a good example of diffraction. b) this is an example of dispersion and not diffraction. c) this is an example of refraction and not diffraction. d) this is an example of reflection and not diffraction.

Hydrogen and helium are both members of?

Consider the following position function. find (a) the velocity and the speed of the object and (b) the acceleration of the object. bold r left parenthesis t right parenthesisr(t)equals=left angle 6 t superscript 4 baseline comma 2 t cubed right angle6t4,2t3 for tgreater than or equals≥0