Using an electronic decibel meter, Monique measures the loudness of an acoustic guitar at a distance of 1 meter, and gets a reading of 65 decibels \( (d=65) \) Using the decibel formula, solve: \( 65=10 \log \left(\frac{P}{P_{0}}\right) \) to find the loudness ratio \( \frac{P}{P_{0}} \) Write your answer as a power of 10 like \( 10^{3} \) Next, using the same decibel meter and also from a distance of 1 meter, Monique measures an electric guitar at 100 decibels Using the decibel formula, solve: \( 100=10 \log \left(\frac{P}{P_{0}}\right) \) to find the loudness ratio \( \frac{P}{P_{0}} \) Write your answer as a power of 10 \( \frac{P}{P_{0}}=\square \) How much louder is the electric guitar? Using your answers for the loudness ratios: The electric guitar is Write your answer as a power of 10

A coil with an area of \( 0.6 \mathrm{~m}^{2} \) is held with its axis coinciding with the direction of a magnetic field (surface perpendicular to magnetic field), with a strength of 0.4 T . 8.3 Calculate the magnetic flux.

QUESTION 6 (Start on a new page.) It has been established that the planet Omega has a moon and that the moon of Omega orbits the planet at a height, above the surface of Omega, which is equal to twice the radius of Omega. The mass of planet Omega is \( 3 \times 10^{15} \mathrm{~kg} \) and the mass of its moon is \( 1.5 \times 10^{13} \mathrm{~kg} \). The radius of the planet Omega is \( 8.5 \times 10^{6} \mathrm{~m} \) and the radius of its moon is \( 2.5 \times 10^{5} \mathrm{~m} \). 6.1 Determine the distance between the centre of the planet Omega and the centre of its moon.

8.4 To produce an emf of 9 V , the area of the coil, with its axis coinciding with the direction of a magnetic field (area perpendicular to magnetic field), is halved in 2 minutes from \( 0.6 \mathrm{~m}^{2} \) to \( 0,3 \mathrm{~m}^{2} \). Calculate the number of turns around the coil.

9. Si dejamos caer al suelo una piedra cuya masa es de 4 kg desde una altura de 4 m , ¿Cuál es la energía cinética cuando ya ha recorrido la mitad de la caída a) hacia el suelo? b) CCual es la velocidad cuando alcanza el suelo?

7.2 A beam of light travels from water to plastic. The speed of light in plastic is \( 2,05 \times 10^{8} \mathrm{~m} \cdot \mathrm{~s}^{-1} \). The refractive index of water is 1,33 . Calculate the refractive index of plastic.