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.
The answer is true. I hope that this helps you out!!
Explanation:
There's not enough information in the problem to solve it. We need to know either the initial speed of the lorry, or the time it takes to stop.
For example, if we assume the initial speed of the lorry is 25 m/s, then we can find the rate of deceleration:
v² = v₀² + 2aΔx
(0 m/s)² = (25 m/s)² + 2a (50 m)
a = -6.25 m/s²
We can then use Newton's second law to find the force:
F = ma
F = (7520 kg) (-6.25 m/s²)
F = -47000 N
Answer:
High boiling and melting points: Hydrogen bonds increase the amount of energy required for phase changes to occur, thereby raising the boiling and melting points.
High specific heat: Hydrogen bonds increase the amount of energy required for molecules to increase in speed, thereby raising the specific heat.
Lower density as a solid than as a liquid: Hydrogen bonds increase the volume of the solid by holding molecules apart, thereby decreasing the density
High surface tension: Hydrogen bonds produce strong intermolecular attractions, which increase surface tension
Explanation:
