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# The stylus of a phonograph record exerts a force of 7.7 x 10-2N on a groove of r...

### Question

The stylus of a phonograph record exerts a force of 7.7 x 10-2N on a groove of radius 10-5m. Compute the pressure exerted by the stylus on the groove

### Options

A) 2.45 x 108 Nm-2

B) 3.45 x 108 Nm-2

C) 4.90 x 108 Nm-2

D) 2.42 x 108 Nm-2

### Explanation:

Pressure, $$P = \cfrac{F}{A}$$
$$= \cfrac{F}{\pi r^2}$$
$$= 7.7 \times 10^{-2}$$
$$\pi \times (10^{-5})^2$$
$$= 7.7 \times 10^{-2}$$
$$\pi \times 10^{-10}$$
$$= 2.45 \times 10^8$$ Nm$$^{-2}$$

## Dicussion (1)

• Pressure, $$P = \cfrac{F}{A}$$
$$= \cfrac{F}{\pi r^2}$$
$$= 7.7 \times 10^{-2}$$
$$\pi \times (10^{-5})^2$$
$$= 7.7 \times 10^{-2}$$
$$\pi \times 10^{-10}$$
$$= 2.45 \times 10^8$$ Nm$$^{-2}$$