Alicia intends to swim to a point straight across a 100 m wide river with a current that flows at 1.2 m/s. She can swim 2.5 m/s in still water. At what angle, measured from the upstream direction, must she swim upstream to achieve her goal

θ = 61.3°

She must swim at an angle of 61.3°

Explanation:

Given;

Width of river = 100 m

Alicia speed in still water = 2.5m/s

Current of river = 1.2m/s

The angle for her to achieve her goal can be derived by the summation of velocity in the direction of the current.

Her speed in the opposite direction of the current must be able to neutralise the speed of the current;

2.5cosθ - 1.2 = 0

2.5cosθ = 1.2

cosθ = 1.2/2.5

θ = cosinverse(1.2/2.5)

θ = 61.3°

the focus of lesson 1 is newton's first law of motion - sometimes referred to as the law of inertia. newton's first law of motion is often stated as. an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

explanation:

coil wire, increase current, put iron inside the coil