Aerodynamic drag can be reduced by altering the density of the air and the vehicle speed, but these factors are not easily controlled. Instead, to reduce drag, car manufacturers can make the height and width of the front of the car smaller. ... This shape reduces drag and the forces that try to propel the car backwards
Investigate means to search for something or look in to something
Answer:
Diffraction: Wave Theory
Interference: Wave Theory
Reflection: both particles and wave theories
Refraction: both particles and wave theories
Answer:

Explanation:
Given:
height above the horizontal form where the ball is hit, 
angle of projectile above the horizontal, 
initial speed of the projectile, 
<u>Firstly we find the </u><u>vertical component of the initial velocity</u><u>:</u>



During the course of ascend in height of the ball when it reaches the maximum height then its vertical component of the velocity becomes zero.
So final vertical velocity during the course of ascend:
Using eq. of motion:
(-ve sign means that the direction of velocity is opposite to the direction of acceleration)

(from the height where it is thrown)
<u>Now we find the time taken to ascend to this height:</u>



<u>Time taken to descent the total height:</u>
- we've total height,


- during the course of descend its initial vertical velocity is zero because it is at the top height, so



<u>Now the total time taken by the ball to hit the ground:</u>



Taking notes,because you can read back on what you learned