Answer: a
Explanation: The color of a star is linked to its surface temperature. The hotter the star, the shorter the wavelength of light it will emit. The hottest ones are blue or blue-white, which are shorter wavelengths of light. Cooler ones are red or red-brown, which are longer wavelengths.
Answer:

Explanation:
The change in potential energy can be expressed as:

where K is a constant with a value of
, q1 and q2 are the charges of the proton and the electron and r is the distance between them.
The charge for the proton is
and the charge for the electron is
.
Converting r=1.0nm to m:

Replacing values:


Answer:

Explanation:
The bike's acceleration can be found by using the following suvat equation:

where
v is the final velocity of the bike
u is the initial velocity
a is the acceleration
s is the distance covered
For the bike in the problem,
u = 0
v = 7 m/s
d = 40 m
Solving the equation for a, we find the acceleration:

Answer:
0.000625 V
Explanation:
The formula linking current , resistance and voltage is :
V = I/R
Voltage = Current / Resistance
Now we substitute values given in question :
Voltage = 0.250 / 400
Voltage (V) = 0.000625
Our final answer is 0.000625 V
Hope this helped and have a good day