A projectile is shot horizontally from the edge of a cliff, 400 m above the ground. The projectile is traveling horizontally at 65 m/s the moment it leaves the cannon. What is the initial vertical velocity of the projectile?

Determine the time taken by the projectile to hit the ground.

How far does the projectile land from the base of cliff?

Find the vertical component of the velocity just before the projectile hits the ground.

What is the magnitude of the final vector velocity the instant before it hits the ground?

What is the direction of the final vector velocity the instant before it hits the ground?

a)   = 0,  b)  t = 9.035 s, c) x = 587.275 m, d)  v_y = -88.54 m / s,

e) v = 109.84 m / s,  f)  θ = -53.7º

Explanation:

This exercise is a projectile launch

a) as the projectile is launched horizontally, its initial vertical velocity is zero

          = 0

b) let's use the relation

          y = y₀ + v_{oy} t - ½ g t²

when reaching the ground y = 0 and the initial vertical velocity is v_{oy}=0

         0 = y₀ + 0 - ½ g t²

         t =

         t =

         t = 9.035 s

c) the horizontal distance is

         x = v₀ₓ t

         x = 65  9.035

         x = 587.275 m

d) the vertical speed when touching the ground

         v_y = -gt

         v_y = 0 - 9.8 9.035

          v_y = -88.54 m / s

the negative sign indicates that the velocity is directed downwards

e) the velocity at this point

          v =

          v =

          v = 109.84 m / s

f) the direction of the velocity

let's use trigonometry

          tan θ = v_y / vₓ

          θ = tan⁻¹1 v_y / vₓ

          θ = tan⁻¹ (-88.54 / 65)

          θ = -53.7º

this angle is measured clockwise

nec chapter 5 contains

c. information on special occupancy areas

nec chapter 6 covers

a. special equipment

which of the following rules contain the words shall or shall not and must be adhered to?

b. mandatory rules

which of the following rules identify actions that are allowed but not required and typically cover options or alternative methods?

c. optional rules

which of the following serves as the introduction to the nec and provides an overview of the book?

a. nec article 90

organizations that test products for safety are

c. nrtls

the nec is published by the

a national fire protection association

the nec is divided into

b. 9 chapters

the nec provides informative annexes for

c. informational materials and examples

two terms from nec article 100 that trainees should become familiar with are

b. labeled and listed

explanation: