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:
B
Step-by-step explanation:
A "or equal to" sign always contains a black colored in circle... With it's pointy end pointing at which direction it is being located.
Answer:
6. 225 feet in 3 minutes = 75 feet in 1 minute (slower)
360 feet in 5 minutes = 72 feet in 1 minute
7. $4 for 5 ounces = $0.80 for 1 ounce (most expensive)
$14 for 20 ounces = $0.70 for 1 ounce
8. 72 people in 6 hours = 12 people in 1 hour
117 people in 9 hours = 13 people in 1 hour (greater rate per hour)
7 memory sticks at 32 mb can hold 491 * 7 = 3437 images.
