Answer: A projectile reaches its highest point when its vertical velocity component is zero.
Step-by-step explanation:
In projectile motion, objects moves in parabolic path.
Projectile motion is a type of motion in which an object moves in a bilaterally symmetrical, parabolic path. Projection motion happens when the force is applied at the start of the trajectory (where the object follows) which follows an interference which is gravity. Gravity takes over and afterwards the object accelerates downwards. The acceleration is constant so the vertical velocity (Vy) varies linearly. The maximum height of the projectile which is the highest height is reached when the vertical velocity (Vy) is equal to zero.
After the projectile reaches its maximum height which is its highest point, it begins to drop downwards.
A letter or symbol is used to represent an unknown quantity
The angle immediately below x makes up the third angle of the isosceles triangle whose base angles are 55°. That third angle and x are "vertical" angles, hence equal. The value of x can be found from the sum of angles of a triangle:
x + 55° + 55° = 180°
x = 70°
The appropriate choice is the 2nd one:
70°
You have to first make like terms
**you want the denominator to be 21
