Answer:
9.1m/s
Step-by-step explanation:
Nate throws a straight ball to Kayla who is standing at a balcony 3.8m above Nate
When she catches the ball, it is still moving upward with a speed of 2.8m/s
v = 2.8m/s
u = ?
s = 3.8m
a= -9.8(The acceleration has a negative sign because the speed of the ball is declining)
Therefore the initial speed at which Nate threw the ball can be calculated as follows
v^2= u^2 + 2as
2.8^2= u^2 + 2(-9.8)(3.8)
7.84= u^2 + (-74.48)
7.84= u^2 - 74.48
u^2= 7.84 + 74.48
u^2= 82.32
u= √82.32
u = 9.1m/s
Hence the initial speed at which Nate threw the ball is 9.1m/s