Answer:
a) 1 m tall, 3 m wide
b) 1 m tall, 1.31 m wide
Explanation:
According to the captain of the spaceship, the dimensions of the picture is the same i.e 1.0 m tall along the y' axis and 3.0 m wide along the x' axis.
b) The dimensions of the picture as seen by an observer on the Earth along the y axis will remain the same, 1.0 m tall, for the direction of the y axis is perpendicular to the spaceship movement.
The dimensions of the picture as seen by an observer on the Earth along the x axis will reduce if we are to go by the Lorentz contraction:
L(x) = L(x)' * √[1 - (v²/c²)]
where
L(x)' = the dimensions of the picture along the x axis on the spaceship,
v² = the speed of the spaceship and c² = the speed of light in the vacuum.
On substituting, we have
L(x) = 3 * √[1 - (0.81c²/c²)]
L(x) = 1.31 m
Electrons
although the conventional current is actually assumed to be a bunch of positive particles moving in the opposite direction
<em>The gravitational force between two objects is inversely proportional to the square of the distance between the two objects.</em>
The gravitational force between two objects is proportional to the product of the masses of the two objects.
The gravitational force between two objects is proportional to the square of the distance between the two objects. <em> no</em>
The gravitational force between two objects is inversely proportional to the distance between the two objects. <em> no</em>
The gravitational force between two objects is proportional to the distance between the two objects. <em> no</em>
The gravitational force between two objects is inversely proportional to the product of the masses of the two objects. <em> no</em>
Efficiency or 
is calculated by formula: 
where 
also efficiency has no unit.
Now put in the data and calculate the efficiency.
The efficiency of the machine is 0.8
If you want to get percentage just multiply by 100 and you get 80%
Hope this helps.
r3t40
