<h2>
After 26.28 seconds projectile returns 26.28 seconds.</h2>
Explanation:
Initial velocity = 450 ft/s = 137.16 m/s
Angle, θ = 70°
Consider the vertical motion of projectile,
When the projectile return to the ground we have
Displacement, s = 0 m
Acceleration, a = -9.81 m/s²
Initial velocity, u = 137.16 x sin70 = 128.89 m/s
Substituting in s = ut + 0.5 at²
s = ut + 0.5 at²
0 = 128.89 x t + 0.5 x (-9.81) x t²
t² - 26.28 t = 0
t ( t- 26.28) = 0
t = 0 s or t = 26.28 s
After 26.28 seconds projectile returns 26.28 seconds.
To solve the problem we will simply perform equivalence between both expressions. We will proceed to place your units and develop your internal operations in case there is any. From there we will compare and look at its consistency


At the same time we have that



Therefore there is not have same units and both are not consistent and the correct answer is B.
Answer: See photo
Explanation: There are a couple of ways to use velocity in an equation in the photo.
Explanation:
<em>The height of the pendulum is measured from the lowest point it reaches (point 3). </em>
At 1, the kinetic energy of the pendulum is zero (because it is not moving), and it has maximum potential energy.
At 2, the pendulum has both kinetic and potential energy, and how much of each it has depends on its height—smaller the height greater the kinetic energy and lower the potential energy.
At 3, the height is zero; therefore, the pendulum has no potential energy, and has maximum kinetic energy.
At 4, the pendulum again gains potential energy as it climbs back up, Again how much of each forms of energy it has depends on its height.
At 5, the maximum height is reached again; therefore, the pendulum has maximum potential energy and no kinetic energy.
Hope this helps :)