Aidez moi s’il vous plaît je bloque sur cette exercice : Le trophée de la Coupe du
monde de football pèse 6,175 kg.
Il est en or 18 carats.
Donnée Pourcentage massique
d'or pur dans l'or 18
carats : 75 %
a. Calculer le nombre d'atomes d'or.
b. Calculer la quantité de matière
d'or correspondante.

Abasketball star covers 2.65 m horizontally in a jump to dunk the ball. his motion through space can be modeled precisely as that of a particle at his center of mass. his center of mass is at elevation 1.02 m when he leaves the floor. it reaches a maximum height of 1.90 m above the floor and is at elevation 0.910 m when he touches down again. (a) determine his time of flight (his "hang time"). (b) determine his horizontal velocity at the instant of takeoff. (c) determine his vertical velocity at the instant of takeoff. (d) determine his takeoff angle. (e) for comparison, determine the hang time of a whitetail deer making a jump with center-of-mass elevations yi = 1.20 m, ymax = 2.45 m, and yf = 0.750 m.

An alarm clock has a current of 4.5 amps and a resistance of 3.2 ohms. what is the voltage in the circuit? a.1.4 volts b.0.71 volts c.14 volts d.46 volts

Aball is thrown vertically upwards from the top of a tower with a speed of 100m/s. it strikes the pound near the base of the tower after 25sec . the height of the tower is