Answer:
38.6 mi/h
Explanation:
7.4 mi/h = 7.4mi/h * (1/60)hour/min * (1/60) min/s = 0.00206 mi/s
Let v (mi/s) be your original speed, then the time t it takes to go 1 mi/s is
t = 1/v
Since you increase v by 0.00206 mi/s, your time decreases by 15 s, this means
t - 15 = 1/(v+0.00206)
We can substitute t = 1/v to solve for v

We can multiply both sides of the equation with v(v+0.00206)
v+0.00206 - 15v(v+0.00206) = v

v = -0.01278 or v = 0.01
0724 mi/s
Since v can only be positive we will pick v = 0.010724 mi/s or 0.010724*3600 = 38.6 mi/h
Answer:
"The distance between crests is 3 cm."
Explanation:
If he writes down "The distance between crests is 3 cm."
That means he is describing the wavelength of a wave and not longitudinal wave. He ought to write something about " direction "
Longitudinal waves are waves in which the displacement of the medium is in the same direction as, or parallel to, the direction of propagation of the wave. While
Wavelength is the distance between the two successfully Crest or trough
Answer:
is B because 35 times 2.9 equals 101.5 and if you round it is 102
Answer:
3N not 0N (first blank)
3N (second blank)
0N (third blank)
Explanation:
1st blank - If a force equals 0, it is balanced.
2nd blank - If one force of 3 Newtons is pushing to the left and another force of 3 Newtons is pushing from the right it wouldn't go anywhere, so it would be balanced at zero.
3rd blank - It would be 0N because forces of the same amount pushing opposite directions would be balanced.