Replication, Multiplication, and Substitution.
Answer:
The rate of the boat in still water is 44 mph and the rate of the current is 4 mph
Explanation:
x = the rate of the boat in still water
y = the rate of the current.
Distance travelled = 120 mi
Time taken upstream = 3 hr
Time taken downstream = 2.5 hr
Speed = Distance / Time
Speed upstream

Speed downstream

Adding both the equations


The rate of the boat in still water is <u>44 mph</u> and the rate of the current is <u>4 mph</u>
The wavelengths of the light are 4.3 * 10^-12 m and 0.2 m respectively.
<h3>What is wavelength?</h3>
The term wavelength has to do with the horizontal distance that is covered by a wave. We know that a long wavelength implies that the wave is able to travel a long distance from one point to another.
Given that;
c = λf
c = speed of light
λ = wavelength of ight
f = frequency of light
Thus;
λ = 3 * 10^8/ 7.00 x 10^19
λ = 4.3 * 10^-12 m
λ = 3 * 10^8/1.50 x 10^9
λ = 2 * 10^-1 or 0.2 m
Learn more about wavelength:brainly.com/question/13533093
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Missing parts:
What are the wavelengths of electromagnetic wave in free space that have the following frequencies? (a) 7.00 x 10^19 Hz______ pm (b) 1.50 x 10^9 Hz__________ cm
Answer:
F = 39.36 N
Explanation:
given,
initial speed, u = 38 m/s
final speed, v = 0 m/s
mass of ball = 0.145 Kg
time, t = 0.14 s
Force = ?
using impulse formula
J = change in momentum
J = F x t
m(v - u) = F x t
0.145 x (0 - (-38)) = F x 0.14
F x 0.14 = 5.51
F = 39.36 N
force exerted by the ball is equal to 39.36 N.
I think the answer is b. easy to digest.
C. and D. are chemical properties,