Question

Pierre conduit une voiture à vitesse constante sur une portion d'autoroute rectiligne. Il parcourt 450 m pendant une durée égale à 9500 ms. Puis, à la même vitesse, il aborde un virage en arc de cercle. 1. Calculer la vitesse de Pierre dans : a) Le référentiel lié à la voiture. B) Le référentiel lié à la route. 2. Quelle est la trajectoire de Pierre dans le référentiel lié à la route ? 3. En déduire la nature du mouvement de Pierre dans ce même référentiel.

Answer 1

Pierre's velocity in the reference frame of the car is 47.37 m/s, and in the reference frame of the road, it is also 47.37 m/s. Pierre's trajectory in the reference frame of the road is curved, indicating circular motion.

Step-by-step explanation:

1a) To calculate Pierre's velocity in the reference frame of the car, we can use the formula:

Vc = d/t

Where Vc is the velocity in the reference frame of the car, d is the distance traveled, and t is the time taken. Given that Pierre travels 450 m in 9500 ms, we can plug these values into the formula:

Vc = 450 m / 9.5 s = 47.37 m/s

1b) To calculate Pierre's velocity in the reference frame of the road, we need to take into account the curvature of the turn. Since the velocity is constant in both cases, the magnitude of Pierre's velocity in the reference frame of the road will be the same: 47.37 m/s.

2. In the reference frame of the road, Pierre's trajectory will be curved, following the arc of the circle.

3. Since Pierre's trajectory is curved in the reference frame of the road, his motion can be classified as circular motion.

Answer 2

• Translated from French language:

"Pierre drives a car at constant speed on a stretch of straight highway. It travels 450 m for a duration equal to 9500 ms. Then, at the same speed, he tackles a turn in an arc. 1. Calculate Pierre's speed in: a) The frame of reference related to the car. B) The road-related frame of reference. 2. What is Pierre's trajectory in the frame of reference linked to the road? 3. Deduce the nature of Pierre's movement in this same frame of reference."