Question

9. Un coche de carreras tiene una velocidad inicial de 4 m/s al sur y

experimenta una aceleración de 2 m/s², la cual dura 12 segundos.
Calcula:
a) ¿Qué desplazamiento tiene a los 12 segundos?
b) ¿Qué velocidad lleva a los 12 segundos?

Answer 1

At 12 seconds, the car has a displacement of 120 meters south, and its velocity is 28 m/s.

a) To find the displacement, you can use the kinematic equation
`: \( s = ut + (1)/(2)at^2 \)`, where
`\( s \) is displacement`,
`\( u \)` is initial velocity,
`\( a \)` is acceleration, and
`\( t \)` is time.

`\( s = (4 \`,
`\text{m/s})(12 \`,
`\text{s}) + (1)/(2)(2 \`,
`\text{m/s}^2)(12 \`,
`\text{s})^2 \)\( s = 48 \`,
`\text{m} + 72 \`,
`\text{m} \)\( s = 120 \`,
`\text{m} \)`

So, the displacement at 12 seconds is 120 meters.

b) To find the final velocity, use the equation:
`\( v = u + at \)`, where
`\( v \)` is final velocity.

`\( v = (4 \`,
`\text{m/s}) + (2 \`,
`\text{m/s}^2)(12 \`,
`\text{s}) \)\( v = 4 \`,
`\text{m/s} + 24`\,
`\text{m/s} \)\( v = 28 \`,
`\text{m/s} \)`

Question:

9. A racing car has an initial velocity of 4 m/s south and undergoes an acceleration of 2 m/s², which lasts for 12 seconds. Calculate:

a) What displacement does it have at 12 seconds?

b) What velocity does it have at 12 seconds?