Question

Standing on a balcony, you throw your keys to a friend standing on the ground below. 1.1 seconds after you release the keys, they have an instantaneous velocity of 15.8 m/s, directed 60° below the horizontal. What initial velocity did you give them? magnitude:
direction: below the horizon

Answer 1

Well, the horizontal component is constant.

Horizontal V=15.8*cos60= you do it.

Now in the vertical, vf(1.1)=Viv+gt this assumes the keys were thrown downward, there is another solution..

15.8*sin60=Viv+9.8(1.1)
solve for Viv

then, intial velocity= horizonal in x + verticalinitial in y

magnitude= sqrt(hor^2+viv^2)
angledownward= arctan downward/horizontal

Answer 2

but what would the magnitude be and also the direction in degrees

Answer 3

my last two lines show you how to compute. What do you not understand about those lines?

Answer 4

i don't understand what numbers yu plug into this:
magnitude= sqrt(hor^2+viv^2)
angledownward= arctan downward/horizontal

Answer 5

hor= horizontal component found first.
viv= initial vertical velocty, from 15.8*sin60=Viv+9.8(1.1)
arc tan means the angle whose tangent is (vertical velocity initial/horizontal initial)

Answer 6

i don't understand how to get the degree part of this question