Question

Le he regalado a mi hijo un coche de plástico para que se entretenga lanzándolo por el suelo. Lo lanza a una velocidad de 12 m/s, y el coche tan solo es capaz de recorrer 9 metros hasta detenerse. Si el coche tiene una masa de 2kg. ¿Cuál es la fuerza de rozamiento?

Answer 1

16 N

Step-by-step explanation:

Initial speed of a car, u = 12 m/s

Finally, it stops, v = 0

The car covers a distance of 9 meters.

The mass of a car is 9 kg

We need to find the friction force. Friction force always acts in the opposite direction to the direction of motion. It is given by :

F = ma

a is the acceleration of the car. We can find it using third equation of motion as follows :

`v^2-u^2=2as\\\\a=(-u^2)/(2s)\\\\a=(-(12)^2)/(2* 9)\\\\a=-8\ m/s^2`

Net force is given by :

F = ma

`F=2* (-8)\\\\=-16\ N`

So, the force of friction has a magnitude of 16 N.