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kolbaska11 [484]
3 years ago
8

A train travels 67 kilometers in 1 hours, and then 81 kilometers in 5 hours. What is its average speed?

Physics
1 answer:
Naddika [18.5K]3 years ago
4 0
Answer: 24.7 km/h

Explanation:

1) Average speed definition and formula

The average speed is the total distance run divided by the time elapsed:

S = distance / time

2) Distance 1 = 67 km

3) Distance 2 = 81 km

4) Total distance traveled = 67 km + 81 km = 148 km

5) time 1 = 1 hour

6) time 2 = 5 hours

7) total time = time 1 + time 2 = 1 h + 5 h = 6 h

8) Average speed:

S = 148 km / 6 h = 24.7 km/h


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To solve this problem it is necessary to apply the kinematic equations of angular motion.

Torque from the rotational movement is defined as

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Our values are given as

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Using the expression of angular acceleration we can find the to then find the torque, that is,

2\alpha\theta=\omega_f^2-\omega_i^2

\alpha=\frac{\omega_f^2-\omega_i^2}{2\theta}

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With the expression of the acceleration found it is now necessary to replace it on the torque equation and the respective moment of inertia for the disk, so

\tau = I\alpha

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If a train travels 80 miles north, 60 miles east, what’s the magnitude of its total displacement? Find the solution by drawing a
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Answer:

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Please see attached photo for diagram.

In the attached photo, X represents the magnitude of the total displacement of the train.

Thus, we can obtain the value of X by using the pythagoras theory as illustrated below:

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-- When an astronaut has to go outside ... where there's NO air ... and fix something on the International Space Station.

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