Volume= Length X width X height.
Plug in the values for each and solve for the volume.
V= (L)(W)(H)
V=(4cm)(5cm)(10cm).
When rounding you look at the number right after the one you want to round. The tenth place is the one right after the decimal. If the number after it is more than five it goes up by one, it it's less than five it stays the same. So since the number after the 8 is a 3 it stays the same.
The answer is 7.8
The first answer should be correct if not then the second one
To begin with, we can use the formula that links frequency, wavelength and velocity.
Because you already have the wavelength and the frequency, you just need to solve for velocity. You can do this by multiplying each side of the equation by frequency.
Therefore, 400 x 2.5 = 1000m/s.
Hope this helps :)
30 Grams would be your answer (I took the test and got it right)