vi is going in the positive direction (up). (That's my choice). a (acceleration) is going in the minus direction (down). The directions could be reversed.
Givens
vi = 160 ft/s
vf = 0 (the rocket stops at the maximum height.)
a = - 9.81 m/s
t = ????
Remark
YOu have 4 parameters between the givens and what you want to solve. Only 1 equation will relate those 4. Always always list your givens with these problems so you can pick the right equation.
Equation
a = (vf - vi)/t
Solve
- 32 = (0 - 160)/t Multiply both sides by t
-32 * t = - 160 Divide by -32
t = - 160/-32
t = 5
You will also need to solve for the height to answer part B
t = 5
vi = 160 m/s
a = - 32
d = ???
d = vi*t + 1/2 a t^2
d = 160*5 + 1/2 * - 32 * 5^2
d = 800 - 400
d = 400 feet
Part B
You are at the maximum height. vi is 0 this time because you are starting to descend.
vi = 0
a = 32 m/s^2
d = 400 feet
t = ??
formula
d = vi*t + 1/2 a t^2
400 = 0 + 1/2 * 32 * t^2
400 = 16 * t^2
400/16 = t^2
t^2 = 25
t = 5 sec
The free fall takes the same amount of time to come down as it did to go up. Sort of an amazing result.
Answer:
The circumference of the yellow circle is 
or 
approximately, the circumference of the blue circle is 
or 
approximately, the circumference of the green circle is 
or 
approximately, the circumference of the red circle is 
or 
approximately, and the circumference of the pink circle is 
or 
approximately.
Step-by-step explanation:
To find the circumference of a circle, you need to multiply the diameter of the circle and multiply it by 
. In this case, the circumferences of the yellow circle are or approximately , the circumference of the blue circle is or approximately , the circumference of the green circle is or approximately , the circumference of the red circle is or approximately , and the circumference of the pink circle is or approximately .
Answer:
nb bhvghvghvhjhkj
Step-by-step explanation:
bjnbhv hgv
