Question

A train is moving at a constant velocity of `"5 m/s"`. After it exists a tunnel, it starts to accelerate with an acceleration of `"9 m/s"^2` for `"5 s"`. What is the velocity of the train after `"5 s"` ?

Answer 1

`50` `"m/s"`

Explanation:

We're asked to find the velocity of the train after `5` `"s"` with a given initial velocity and acceleration.

To solve this, we can use the equation

`v_x = v_(0x) + a_xt`

where

• `v_x` is the velocity at time `t` (what we're trying to find)

• `v_(0x)` is the initial velocity (`5` `"m/s"`)

• `a_x` is the acceleration (`9` `"m/s"^2`)

• `t` is the time (`5` `"s"`)

Plugging in known values, we have

`v_x = 5"m/s" + (9"m/s"^2)(5"s") = color(red)(50` `color(red)("m/s"`

The final velocity (the velocity at time `t = 5` `"s"`) is thus `color(red)(50` meters per second.