The height (in meters) of a projectile shot vertically upward from a point 2 m above ground level with an initial velocity of 25.5 m/s is h = 2 + 25.5t ? 4.9t2 after t seconds. (Round your answers to two decimal places.) (a) Find the velocity after 2 s and after 4 s. v(2) = 5.9 Correct: Your answer is correct. m/s v(4) = -13.7 Correct: Your answer is correct. m/s (b) When does the projectile reach its maximum height? 2.60 Correct: Your answer is correct. s (c) What is the maximum height? 37.2 Incorrect: Your answer is incorrect. m (d) When does it hit the ground? 5.36 Incorrect: Your answer is incorrect. s (e) With what velocity does it hit the ground? 27.03 Incorrect: Your answer is incorrect. m/s

a) , , b) , c) , d) , e)

Explanation:

a) The velocity function is determined by deriving the position function in time:

Velocities after 2 seconds and 4 seconds are, respectively:

b) The maximum height is reached when velocity is equal to zero:

The time when the projectile reaches the maximum height:

c) The maximum height is:

d) The projectile hits the ground when height is equal to zero:

The roots of the second order polynomial are presented below:

The first one is the only reasonable solution in physical terms.

e) The velocity of the projectile when it hits the ground is:

the force on the thing and the distance the force moves the thing

c because the news are a source of information of things that happen on the daily and shows evidence about that particular topic