Answer:
0.0192A
Explanation:
Since, the reading of the galvanometer is 0 A, the voltage across the resistance R will be:
Step 1
VR = V2
VR = 3.00v
Step 2
Calculating the current through the resistance R as below,
IR = V1 - V2 /R1
IR = 12 - 3 /468
IR =0.0192A
Answer:
a) 
b) imagen adjunta
Explanation:
a) Primero debemos hacer la conversión de 81 km/h a m/s, esto es 22.5 m/s.
Ahora, usando la ecuacion cinemática, en un movimiento acelerado tenemos:

Queremos encontrar la posición hasta detenerse, osea vf = 0.



b) Para este caso el gráfico se encuentra adjunto.
Espero que te sirva de ayuda!
The lower the frequency the lower the pitch sound.
The fraction of energy that is lost is 25%, it depends how fast the ball was going until it lost 25% of its energy, the gravitational energy was transferred into the kinetic energy that helped the ball bounce back