Answer:
# of Snickers bars 2
Explanation:
Power output= 0.30 HP
=0.3*746
= 0.30 HP (746 W=1.00 HP)
= 224 W
time required 2 h 49 m = 10140 seconds
Since power is work divided by time, then work is:
Work done by the jet = P*t
= 224 *(10140)
= 2.3 MJ (2.3 x J)
Converting MJ to Cal
2.3 MJ=549 Cal
# of Snickers bars = 549 Cal / 280 Cal
= 2.0 bars (rounded from 1.96)
Answer:
If the canoe heads upstream the speed is zero. And directly across the river is 8.48 [km/h] towards southeast
Explanation:
When the canoe moves upstream, it is moving in the opposite direction of the normal river current. Since the velocities are vector (magnitude and direction) we can sum each vector:
Vr = velocity of the river = 6[km/h}
Vc = velocity of the canoe = -6 [km/h]
We take the direction of the river as positive, therefore other velocity in the opposite direction will be negative.
Vt = Vr + Vc = 6 - 6 = 0 [km/h]
For the second question, we need to make a sketch of the canoe and we are watching this movement at a high elevation. So let's say that the canoe is located in point 0 where it is located one of the river's borders.
So we are having one movement to the right (x-direction). And the movement of the river to the south ( - y-direction).
Since the velocities are vector we can sum each vector, so using the Pythagoras theorem we have:
