a voltmeter's pointer is 3 cm in length. find the degrees through which is rotates when it moves 1.1 cm on the scale?
s = rθ
1.1 = 3θ
θ = .366666 radians = 21°
To find the number of degrees through which a voltmeter's pointer rotates when it moves a certain distance on the scale, we can use trigonometry.
Here's how to do it:
1. Determine the radius of the voltmeter's scale: The length of the pointer is given as 3 cm. The scale of a voltmeter is typically circular, so the length of the pointer is equal to the radius of the scale.
2. Calculate the circumference of the scale: The formula for the circumference of a circle is C = 2πr, where C is the circumference and r is the radius. Substitute the value of the radius from step 1 into the formula to find the circumference.
3. Convert the distance moved to a fraction of the circumference: Divide the distance moved (1.1 cm) by the circumference calculated in step 2. This will give you the fraction of the scale covered by the pointer when it moves 1.1 cm.
4. Convert the fraction to degrees: Since there are 360 degrees in a full circle, multiply the fraction from step 3 by 360 to obtain the number of degrees through which the pointer rotates.
By following these steps, you should be able to determine the number of degrees through which the voltmeter's pointer rotates when it moves 1.1 cm on the scale.