Answer:
635 years old
Explanation:
The light reaching the earth from the sun will travel at a speed called the speed of light, and this has a universal value of 3 × 10⁸ m/s. Bearing this in mind, let us calculate the age of the light reaching the Earth from the sun:
Distance of star from Earth = 6.1 × 10⁸m
Speed of light = 3 × 10⁸ m/s
We have distance and speed, let us calculate the time of travel of the light from the star to the earth.
Distance = speed × time
6.1 × 10⁸ = 3 × 10⁸ × time

In order to do the division above, we will divide the whole numbers normally, then we will apply the law of indices to the power that says:
Xᵃ ÷ Xᵇ = X⁽ᵃ⁻ᵇ⁾

Next, we are told that there are 3.2 × 10⁷ seconds in a year.
∴ The number of years travelled by the light from the star:

please note that:
2.03 × 10¹⁰ = 20300000000
3.2 × 10⁷ = 32000000

The closest answer in the option is 635 years, and we are short of this by some points due probably to approximations in the calculation.
Answer:
The velocity is 
Explanation:
From the question we are told that
The diameter of the pipe is 
The magnetic field is 
The hall voltage is 
Generally the average fluid velocity is mathematically represented as

=> 
=> 
Answer:
(a) -16.7 N s; (b) -167 N
Explanation:
Given: m = 0.530 kg; vi = 18.0 m/s; vf = 13.5 m/s; t = 0.100 s
Find: (a) Impulse, (b) Force
(a) Impulse = Momentum Change = m•Delta v = m•(vf - vi)= (0.530 kg)•( -13.5 m/s - 18.0 m/s)
Impulse = -16.7 kg•m/s = -16.7 N•s
where the "-" indicates that the impulse was opposite the original direction of motion.
(Note that a kg•m/s is equivalent to a N•s)
(b) The impulse is the product of force and time. So if impulse is known and time is known, force can be easily determined.
Impulse = F•t
F = Impulse/t = (-16.7 N s) / (0.100 s) = -167 N
where the "-" indicates that the impulse was opposite the original direction of motion.