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:
y ≥ -5
Explanation:
y is greater than -5 because the darkened line is heading towards the positive side.
(The positives are greater than the negatives.)
(The smaller negative numbers are greater than the larger negative numbers.)
Answer:33
Step-by-step explanation:
3850/(155-45)
=3850/115
=33.4
Round up to 33.
Hope this helps and please follow me;)
The equivalent of 4 meters is 4.374 yards
Answer: 28
Step-by-step explanation:
Given
Kenny made 7 serves over the net for every 2 serves that did not go over the net i.e. success rate of Kenny is
for 36 serves, applying the same success rate, it is
Serves that did not make over the net is 
Thus, Kenny will make 28 serves that make over the net
