Answer:
2070m/s
Step-by-step explanation:
frequency=900HZ
Wavelength=2.3m
now,
speed of wave= frequency × wavelength =900×2.3
=2070m/s
ANSWER
Answer:
The length of the rectangle is 15 cm.
Step-by-step explanation:
breadth(b)=?
length(l)= 3+2b
perimeter(P)= 42 cm
Now,
P = 2 ( l+b )
or, 42= 2 ( 3+2b+b)
or, 42 = 2 ( 3+3b)
or,
= 3+3b
or, 21 = 3+3b
or, 21-3 =3b
or, 18 = 3b
or,
= b
or, 6 = b
Here, Breadth(b)= 6 cm
Length (l) = 3 + 2*6
= 3 + 12
=15 cm
I'm sorry I'm too lazy to read all of that. However, I did get the main point. The river was going at 3 mph. Since he wanted to travel 10 miles upstream and downstream, you would have to subtract 20 by 3. This would mean he was going at a speed of 17 mph.
Step-by-step explanation:
7e=the money she makes from earrings
13n=the money she makes from necklace