I believe it’s A. I know for sure it isn’t D.
        
             
        
        
        
Answer:
a. t = 1.43 s
b. d = 7.88 m
Explanation:
a. The time of flight can be found using the following equation:

Where:
 : is the final height = -10 m
: is the final height = -10 m 
 : is the initial height = 0
: is the initial height = 0
 : is the initial speed in the vertical direction = 0
: is the initial speed in the vertical direction = 0
g: is the acceleration due to gravity = 9.81 m/s²
By solving the above equation for "t" we have:

Hence, the ball will hit the ground in 1.43 s.
b. The distance in the horizontal direction can be found as follows:

Where:
x₀: is the initial position in the horizontal direction = 0
a: is the acceleration in the horizontal direction = 0 (it is moving at constant speed)

Therefore, the ball will travel 7.88 m before it hits the ground.
I hope it helps you!
 
        
             
        
        
        
Kinetic energy.
Kinetic energy is the type of energy observed in moving objects. In this case the football player is running, ie moving, so he/she must have kinetic energy. 
 
        
             
        
        
        
The answer is:
C. 361 m/s
The explanation:
To calculate  the speed of sound at a given temperature (50°C) we are going to use this formula:
v = 331 + 0.6T
when V is the velocity
and T is the temperature = 50°C
by substitution:
v = 331 + 0.6(50)
v = 361 m/s
So, The correct answer is C.
because of the variation of the motion of the molecules of air with change of temperature so, the velocity (V) of the  sound in the air is change with temperature.