# University of physics

I don’t understand this Physics question and need help to study.

Please answers theses questions

1.Write the following numbers in scientific notations with the appropriate number of significant digits:

a.172.0 = __ __

b.0.0023 = __ __

c.8.032 = __ __

d.0.103 = __ __

2.Perform the operations and write the answers in scientific notation with the appropriate number of significant digits:

a.27.39 x 0.0320 = __ __

b.62.304/2.93 = __ __

c.0.032 + 12.19 = __ __

d.(7.30 – 5.1)/12.083 = __ __

e.(39.04 + 16.317)/(0.0341 + 0.207) = __ __

3.Convert: (write the answer with the correct number of significant digits)

a.329.6 cm^{3} = __ __ m^{3}

b.62.7 mi/s = __ __ m/s

c.0.72 yard^{3} = __ __ m^{3}

4.A house painter uses a 9.0 inch wide “roller” which is 5.0 inches in diameter to paint a wall surface 2.40 m x 6.70 m. The surface includes 2 windows (2.0 ft x 3.0 ft each) which, obviously, should not be painted. What is the minimum number of times that the painter has to roll his “paint roller” (one full circle for each roll) in order to apply one layer of paint on the surface to be painted?