Answer:
90 J
Explanation:
W=fd
W=(75)(1.2)
W= 90 J
Answer:
Average velocity = 30 miles per hour
Explanation:
Given that
Velocity for uphill = 20 miles per hour
Velocity for downhill = 60 miles per hour
We know that
Distance = Velocity x time
Total distance = Average velocity x total time
Lets take distance from home to school is s
Time taken from home to school= s/20 hr
Time taken from school to home= s/60 hr
Total time =s/20+s/60
Total distance = Average velocity x total time
s + s = Average velocity x (s/20+s/60)
So average velocity = 30 miles per hour
Answer:
b) The star is moving away from us.
Explanation:
If an object moves toward us, the light waves it emits are compressed - the wavelength of the light will be shorter, making the light bluer. On the other hand, if an object moves away from us, the light waves are stretched, making it redder. If from laboratory measurements we know that a specific hydrogen spectral line appears at the wavelength of 121.6 nanometers (nm) and the spectrum of a particular star shows the same hydrogen line appearing at the wavelength of 121.8 nm, we can conclude that the star is moving away from npos, since the wavelength related to that star is more expanded.
