SOMEONE EXPLAIN If |a+b] = |a-b| then angle between 1 and Bis. ( (a) 0° (b) 45° (c) 90° (d) 180°​

Agroup of monkeys is trying to cross the river in a rowboat. the maximum buoyant force on the rowboat is 2,000 n. the weight of the rowboat is 1,000 n. each monkey has a weight of 150 n. how many monkeys can safely cross in the rowboat at one time? explain your reasoning, including any calculations you used to find the answer.