Answer:
9R
Explanation:
We know that the resistance is
.
If we stretch the wire to a new length L2 = 3L, the cross-sectional area will also change. If the cross-sectional area doesn't change throughout the wire, we can say that:
Volume = L*A = 3L * A2 being A2 the new area after stretching the wire.
Since the volume remains the same we conclude that A2 = A/3
With this information, we calculate the new resistance:

Since
, and by simple inspection of the previous equation, we get:
<em>R2 = 9*R</em>
Average speed = (total distance covered) / (time to cover the distance)
Ian's total distance covered = (2km + 0.5km + 2.5km) = 5 km.
His time to cover the distance = 3 hours.
Average speed = (5 km) / (3 hrs)
Average speed = (5/3) (km/hr)
<em>Average speed = 1.67 km/hr</em>
Answer:

Explanation:
If the weight is a linear function of the amount of fuel, the following correlation is fulfilled :

we solve the equation:

At the most distant point, the size of the speed is zero (0 m/s). This is a direct result of preservation of vitality. PE = KE. The most distant far from the harmony position is the maximum PE. Hence it can have no KE. No KE implies no speed since KE = .5mv2