Would like some help with the following please: A ship drops anchor in a harbor. The anchor is 49 ft. above the surface of the water when it is released.

Question

Use the vertical motion formula h = -16t² +vt + s to answer the following questions.

 

a. What is the value of x, the starting height.  (49 feet above the surface of the water)

 

b. What is the value of h when the anchor hits the water

 

c. The starting velocity is zero. After how many seconds will the anchor hit the water

Answer 1

The starting height x (which is also "s" in your original equation) is 49, as you said.  So now the equation becomes

 

h = -16t² + vt + 49

 

The value of h when the anchor hits the water would be 0 (negative values would be underwater).  Since the starting velocity ("v" in the equation) is also 0, our equation will then be:

 

0 = -16t² + (0)t + 49

or

16t² = 49

 

Divide by 16 and take the square root to find t, which is the time it takes to hit the water.