Answer:
t_a = 7 s
t_w = 5 s
Step-by-step explanation:
Given:
- The average speed in air v_a = 16 m/s
- The average speed in water v_w = 3 m/s
- The total distance D = 127 m
- The total time T = 12 s
Find:
How long did the stone fall in air and how long did it fall in the water?
Solution:
- Lets time taken by stone to drop through air as t_a = t_a.
- The time taken in water would be t_w = (12 - t_a)
- The total distance covered can be calculated as:
D = v_a*t_a+ v_w*(12 - t_a)
127 = 16*t_a + 3*(12 - t_a)
Simplify and solve for t:
91 = 16*t_a - 3t_a
13*t_a = 91
t_a = 7 s
t_w = 5 s
9514 1404 393
Answer:
11
Step-by-step explanation:
The future value of the account is given by the formula ...
A = P(1 +r/12)^(12t) . . . . principal P invested at rate r for t years
Solving for t, we find ...
A/P = (1 +r/12)^(12t) . . . . . . . . . . . divide by P
log(A/P) = 12t·log(1 +r/12) . . . . . . take logs
Divide by the coefficient of t, then fill in the numbers.
t = log(A/P)/(12·log(1 +r/12)) = log(202800/93000)/(12·log(1 +.068/12))
t ≈ 11.497
It will take about 11 years for the account balance to reach the desired amount.
Answer:
22.86
Step-by-step explanation:
2.54 x 9 will give you the answer.
Answer:
A
Step-by-step explanation:
56-70+70-21
126-91
35
