A rain drop falls at a constant vertical velocity of 1.8m/s in still air and a horizontal wind is blowing. If the velocity of the wind is 1.4m/s, determine the magnitude and direction of the resultant velocity of the rain drop.
I found the magnitude of the resultant using Pythagoras but I can't find the angle using trigonometry because I dot know what to the base and perpendicular are.
I found the magnitude of the resultant using Pythagoras but I can't find the angle using trigonometry because I dot know what to the base and perpendicular are.
The sides you use in trig formulae depend on the angle you choose in the first place. There are three sides; the side opposite your angle, the side adjacent to your angle, and the hypotenuse.
You choose your angle, and can use the mnemonic SOH CAH TOA to remember the order -
sinθ=hypotenuseopposite
cosθ=hypotenuseadjacent
tanθ=adjacentopposite
So in this case, choose your angle, work out which side is opposite to it and adjacent (next) to it, and plug in your values
The sides you use in trig formulae depend on the angle you choose in the first place. There are three sides; the side opposite your angle, the side adjacent to your angle, and the hypotenuse.
You choose your angle, and can use the mnemonic SOH CAH TOA to remember the order -
sinθ=hypotenuseopposite
cosθ=hypotenuseadjacent
tanθ=adjacentopposite
So in this case, choose your angle, work out which side is opposite to it and adjacent (next) to it, and plug in your values
I think he's confused at which value is which, not what the sides are called and how to apply trig.
@OP, you have 1.8m/s going vertically down, and 1.4m/s going horizontally, you can draw a right angled triangle and find the angle from the vertical.
I think he's confused at which value is which, not what the sides are called and how to apply trig.
@OP, you have 1.8m/s going vertically down, and 1.4m/s going horizontally, you can draw a right angled triangle and find the angle from the vertical.
Ah right! Though from the diagram it should be clear which value is which, and given the talk about 'base' and 'perpendicular', I wasn't sure whether or not they were clear on using trig