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3 years ago

10

a red kangaroo can hop at speeds of 65 km/hr. how much time will it take the kangaroo to hop 0.25 km at that speed?

1 answer:

daser333 [38]3 years ago

3 0

Time = (distance) / (speed)

Time = (0.25 km) / (65 km/hr)

<em>Time = 0.00385 hour</em>

(That's 13.85 seconds.)

<u />

<u>Better way:</u>

Distance = 0.25 km

Distance = 250 meters

Speed = (65 km/hr) x (1000 m/km) x (1 hr/3600 sec)

Speed = 18.06 m/sec

Time = (250 m) / (18.06 m/s)

<em>Time = 13.85 seconds </em>

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The mass of the cargo is $M = 188.43 \ kg$

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From the question we are told that

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a. $\Delta s ^2 = 8.0888 \ 10^{17} m^2$

b. $\Delta s ^2 = 3.0234 \ 10^{16} m^2$

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The spacetime interval $\Delta s^2$ is given by

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$\Delta s ^2 = - \Delta (c t) ^ 2 + \Delta \vec{x}^2$ .

Lets work with the signature ( + - - - ), and, if needed in the other signature, we can multiply our interval by -1.

<h3>a.</h3>

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$\Delta \vec{x}^2 = 5,625 m^2$

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<h3>b.</h3>

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