For martians to destroy human society, they would need to travel 49,667,440 miles.
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
Answer:
Jeff mows 9 yards of lawn in 30 minutes
Step-by-step explanation:
The equation that models the amount of time (t) in minutes it takes Jeff to mow an average sized yard is 
, where n is the number of yards he mows.
To find the number of yards Jeff mows in 30 minutes, we set the equation to 30 and solve for n.
Add -12 to both sides:
Divide both sides by 2
Hence Jeff mows 9 yards of lawn in 30 minutes.
Answer:
13.7142857143
Step-by-step explanation:
If you need to round then do so, or i will comment the rounded version if needed.
