Answer:
51.96 years
2) 30 million of years
Explanation:
First we must know the travel time of the ship seen from the earth. The spaceship travels at half the speed of light, this means that the amount of time the spacecraft must spend to travel the same distance is double compared to the light, that is 60 years.
Now due to the speed of the ship, we must take into account relativistic effects, such as time dilation, this is given by:

Where t is the time measured in the ship, t' is the time measured in the earth, inertially moving with velocity v.
Rewriting for t:

This is the amount of time it would take you reach the Whirlpool galaxy in the spaceship.
2) a light year is a measure of distance, which indicates the kilometers that light travels in a year. Thus, the light emitted by Whirlpool galaxy takes 30 million of years reaches our planet.
Answer:
3.014 x 10⁻⁸ N
Explanation:
q = magnitude of charge on the supersonic jet = 0.55 μC = 0.55 x 10⁻⁶ C
v = speed of the jet = 685 m/s
B = magnitude of magnetic field in the region = 8 x 10⁻⁵ T
θ = angle between the magnetic field and direction of motion = 90
magnitude of the magnetic force is given as
F = q v B Sinθ
F = (0.55 x 10⁻⁶) (685) (8 x 10⁻⁵) Sin90
F = 3.014 x 10⁻⁸ N
The absence of external force in the outer space, allows the piece of rock to continue moving at the same velocity for thousands of years.
<h3>Absence of external force on the outer space</h3>
The outer space is almost an absolute vacuum, because it's nearly empty. There is no matter such as air in the outer space that will provide an external force needed to change the velocity of the piece of rock.
From Newton's first law of motion, an object in a state of rest or uniform motion in a straight line, will continue in that state unless it is acted upon by an external force.
Thus, the absence of external force in the outer space, allows the piece of rock to continue moving at the same velocity for thousands of years.
Learn more about outer space here: brainly.com/question/24701339
Answer:
u = - 38.85 m/s^-1
Explanation:
given data:
acceleration = 2.10*10^4 m/s^2
time = 1.85*10^{-3} s
final velocity = 0 m/s
from equation of motion we have following relation
v = u +at
0 = u + 2.10*10^4 *1.85*10^{-3}
0 = u + (21 *1.85)
0 = u + 38.85
u = - 38.85 m/s^-1
negative sign indicate that the ball bounce in opposite directon