Solve the all parts of given problem:
Problem: A river flows due south with a speed of 1.6m/s. A man steers a motorboat across the river; his velocity relative to the water is 4.6m/s due east. The river is 670m wide.
Part A: What is the magnitude of his velocity relative to the earth?
Part B: What is the direction of his velocity relative to the earth?
Part C: How much time is required to cross the river?
Part D: How far south of his starting point will he reach the opposite bank?
I need help to find the magnitude of his velocity relative to the earth and express your answer using two significant figures.