Answer:
False, because current flow has no effect in the weight of a conductor.
Explanation:
Current flow has no effect in the weight of a conductor. Thus, the weight on the scale will be the same when current is flowing and when current is not flowing in the copper tube.
Therefore, If a copper tube has current flowing to the right in the presence of a magnetic field going forward ("into the board"), we expect the weight on the scale to be the same whether current is flowing or not.
Answer: 4 s
Explanation:
Given
The applied force is 70 N
mass of the rock is 28 kg
initial velocity 
final velocity 
Deceleration provided by force is

using the equation of motion

3.8 is the smallest number because if you multiple the others would be large
B. Earth’s outer surface is cooler than its interior layers.
Explanation:
- The option given above is showing us that the temperature in the interior of the earth is higher than the temperature in the outer layer.
- There is travel of heat from the inner core of the earth to the earth's crust. Due to the loss of heat when it reaches the outer layer, there arises a temperature difference.
- The heat loss is due to the absorption of heat during its transfer. Hence, option B is the answer.