Answer:
Power required will be 7.2 watt
Explanation:
We have given battery of Barble jeep is 6 volt
So potential difference V = 6 volt
Resistance of electric motor R = 5 ohm '
We have to find the power motor using to drive the jeep
Power is given by
, here V is voltage and R is resistance
So 
It should be Constant speed. The line goes straight & doesn’t change within the graph.
Joseph's experiment could be improved by using the same antenna at each part of the house during each trial instead of using different antenna. By doing so, he can obtain accurate results how is the signal in different part of the house under the same conditions (despite the location). So, he will see the dependence of the signal on the location. If he uses different antenna, than this antenna can also have influence of the signal.