Answer:
E = 3.8 kJ
Explanation:
Given that,
The mass of the object, m = 10 g = 0.01 kg
The heat of fusion of aluminum is 380 kJ/kg
We need to find the energy required to melt the mass of the aluminium. It can be calculated as follows:
E = mL
So,
E = 0.01 × 380
E = 3.8 kJ
So, the energy required to melt the mass is equal 3.8 kJ.
Answer:

So a=3.844 and b=5
Explanation:
Scientific notation requests to write a number using powers of ten as a factor accompanying a real number (a) between 1 and smaller than 10 that contains the digits to exactly represent the original number. So in this case, the number 384,400 can be written as:

with a=3.844, and "5" as the exponent of ten (so b=5)
The answer for that would be C
Answer:

Explanation:
Starting from the equation:

First of all, let's multiply by t on both sides:

And then, let's divide by v on both sides:

So, finally

This shifts the star’s spectral lines toward the blue end of the spectrum. If the star is moving away from us, it’s waves are effectively stretched out when they reach earth, increasing their wavelength. This shifts the star’s spectral lines toward the red end of the spectrum.