Une plateforme à roulettes de 48 kg est accrochée à un ressort horizontal dont la constante de rappel est de 20 N/m : l'autre extrémité du ressort est fixée au mur. Le frottement entre la plate-forme et le plancher est négligeable. On éloigne la plate-forme du mur afin d'allonger le ressort de 1.5 m, puis on la lâche (vitesse initiale nulle). Béatrice, dont la masse est de 65 kg, marche à côté de la plate-forme en s'efforçant d'aller à la même vitesse ; quand la plate-forme est au centre de l'oscillation, elle monte dessus. Calculez l'énergie mécanique de Béatrice et de la plate-forme avant qu'elle n'y monte.

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27

find the sum of the two horizontal vectors and the sum of the two vertical vectors

isoceles right angled triangle

the design of a ski jumping suit involves a trade-off between giving the skiers lift to get higher jumps and ensuring the skier does not face a lot of drag before the jump itself. an expansive suit may to lift the skier higher, but at the same time, it will also increase the air resistance. higher air resistance as the skier goes down the slope limits the speed of the jump. a big suit also increases the risk of losing balance or control, especially if there's a strong gust of wind. while technologically enhanced suits a lot, clothing is not the only factor in a ski jumper’s success. gathering speed while skiing down the slope, ensuring good speed on the ramp, and maintaining good body posture and form in the air all contribute to a ski jumper's success.

i think its d if wrong im sorry