Answer:
1.a) 3.93 m/s
b) 0.80 s
2. a) 8.49 m
b) 0.39 s
Step-by-step explanation:
1. a) The speed at which the fox leaves the snow can be found as follows:

Where:
g: is the gravity = 9.80 m/s²
: is the final speed = 0 (at the maximum height)
: is the initial speed =?
H: is the maximum height = 79 cm = 0.79 m

Hence, the speed at which the fox leaves the snow is 3.93 m/s.
b) The time at which the fox reaches the maximum height is given by:


Now, the time of flight is:

2. a) The maximum height the ball reaches is:

Then, the maximum height is 8.49 m.
b) The time at which the ball passes through half the maximum height is:

Taking y₀ = 0 and
= 8.49/2 = 4.245 m we have:
By solving the above quadratic equation we have:
t = 0.39 s
Therefore, the time at which the ball passes through half the maximum height when the ball is going up is 0.39 s.
I hope it helps you!