- #1

Skyblitz

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A cheetah cah hit 105 km/h in 2s, and maintain this speed for 15 s, while an antelope can reach 90km/h in 2s and sustain this for a long time.. if they are both separated by 100m and the antelope reacts 0.5s after the cheetah starts running, will they meet? and if not, when?

Basically what I did was I calculated how far each would go in the 2s..

for the cheetah:

I basically used the formula X = 0.5at^2

and came up with 58.3m

For the antelope: I came up with 150 m.

(Cheetah is the point of origin).

Then, I basically added 0.5s to the constant velocity of 105 km/h (or 29.1m/s) and found out that in 2.5 s, the cheetah travelled 72.9 m.

Thus, I subtracted the two distances, of 150m - 72.9m and this results in 77m.

Then I set the point of reference so that the antelope is at rest and the cheetah is moving at 4.17m/s (relative to the antelope).

Thus, I calculated that the time would take 18.48 s

Therefore, they would not meet since the cheetah can only run for 15s.

However, it asks how far they are apart.

Therefore, I assume that since the constant velocity of the cheetah is greater than the antelope, at exactly 15s, the cheetah will be the closest.

Therefore, at this point I'm stuck on what to do..

I subtracted 2 from 15 (so 13) multiplied by 4 m/s but that didn't give me the right answer...

(of 26.6m)

Any help is appreciated! :)