Why is the answer A and not C?please help!
1 answer:
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Answer:
(a) The distance of the chicken from the finish line is 62.5 m
(b) The stationary time of the wildebeest is 675 s
Explanation:
Given;
total distance traveled by wildebeest and chicken, d = 2 km = 2000 m
speed of the wildebeest, = 16 m/s
speed of the chicken, = 2.5 m/s
Time for wildebeest to finish the race without stopping, 2000 / 16 = 125 s
Time for chicken to finish the race without stopping, 2000/2.5 = 800 s
(b) for how long in time (in s) was the wildebeest stationary?
t(stationary) = t(chicken) - t(wildebeest)
t = 800s - 125 s
t = 675 s
(a) how far (in m) is the chicken from the Finish Line when the wildebeest resume the race?
The time taken for the wildebeest to run 1.6 km (1600 m) is given by;
t = 1600 / 16 = 100 s
The total time spent by the wildebeest before it resumed the race = stationary time + 100s
t (total) = 675 s + 100 s = 775 s
Distnace traveled by the chicken when the wildebeest resumed the race = 2.5m/s x 775s = 1937.5 m
Thus, the distance of the chicken from the finish line = 2000 m - 1937.5 m
the distance of the chicken from the finish line = 62.5 m
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:
Answer:
T_finalmix = 59.5 [°C].
Explanation:
In order to solve this problem, a thermal balance must be performed, where the heat is transferred from water to methanol, at the end the temperature of the water and methanol must be equal once the thermal balance is achieved.
where:
mwater = mass of the water = 0.4 [kg]
Cp_water = specific heat of the water = 4180 [J/kg*°C]
T_waterinitial = initial temperature of the water = 85 [°C]
T_finalmix = final temperature of the mix [°C]
Now replacing: