Question

A 20,000 kg train starts from rest and goes to 20 m/s in 400s. what is the net force on the train?

Answer 1

To calculate the net force on the train, you can use Newton's second law of motion, which relates force (F), mass (m), and acceleration (a) as follows:

`\[F = m \cdot a\]`

Given:

- Mass of the train (m) = 20,000 kg

- Initial velocity (u) = 0 m/s (starting from rest)

- Final velocity (v) = 20 m/s

- Time (t) = 400 s

First, calculate the acceleration (a) using the following equation, which relates acceleration, initial velocity, final velocity, and time:

`\[a = \frac{{v - u}}{t}\]`

Substitute the values:

`\[a = \frac{{20\, \text{m/s} - 0\, \text{m/s}}}{400\, \text{s}} = \frac{20\, \text{m/s}}{400\, \text{s}} = 0.05\, \text{m/s}^2\]`

Now that you have the acceleration, you can calculate the net force (F):

`\[F = m \cdot a = 20,000\, \text{kg} \cdot 0.05\, \text{m/s}^2 = 1,000\, \text{N}\]`

So, the net force on the train is 1,000 Newtons.