A box with a weight of 50 n rests on a horizontal surface.

How do you work out 21.3-8= show your working. plz

Nathan is an ecologist. he’s studying the effect of secondary consumers on primary consumers. his current research focuses on a population of blue jays and crows. they eat caterpillars and mice. if the number of blue jays increases, what are the likely effects on other populations? 1the number of crows will increase. 2the number of mice will decrease. 3the number of mice will remain the same. 4the number of caterpillars will decrease.

Blank is the amount of energy in a sound wave per unit of time and is also related to the loudness of a sound