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: 12/5 or 2 2/5
Step-by-step explanation: 7/2 - 11
/10
Answer:
312 784
Step-by-step explanation:
if u need this answer, take
The answer of 3542=48, if the given is 1243=21 , 2415=36, 3241=25, 4521=27.
Step-by-step explanation:
The given is,
1243=21
2415=36,
3241=25,
4521=27
Step:1
For, 1243 = 21
Above is solved by,
(1+2)×(4+3)=21
(3)×(7)=21
21=21
For, 2415 = 36
Above is solved by,
(2+4)×(1+5)=21
(6)×(6)=36
36=36
For,3241= 25
Above is solved by,
(3+2)×(4+1)=25
(5)×(5)=25
25=25
For, 4521= 27
Above is solved by,
(4+5)×(2+1)=27
(9)×(3)=27
27=27
For, 3542 = ?
Above is solved by,
= (3+5)×(4+2)
=(8)×(6)
3542=48
Result:
The answer of 3542=48, if the given is 1243=21 , 2415=36, 3241=25, 4521=27.
<span>7/8 = 7 * 1/8 and 1/8 = 1 : 8 = 0.125. After that: 7 * 0.125 = 0.875. Finally, 0.875 > 0.78. We can do it also by transforming 0.78 to fraction: 0.78 = 78/100 = 39/50 and then multiplying the numerator and the denominator by 4: 39/50 = 156 / 200 . Then we will also multiply 7/8 * 25/25 = 175/ 200. Obviously: 175/200 > 156/200. Answer: 7/8 is bigger than 0.78. </span>
