The stiffness of a particular spring is 680 n/m. one end of the spring is attached to a wall. when you pull on the other end of the spring and hold it stretched with a steady force of 133 n, the spring elongates to a total length of 57 cm. what was the relaxed length of the spring? (remember to convert to s. i. units.)

37.4 cm

Explanation:

The force that the spring  exterts when stretched is:

Where x_0 is the relaxed length and k = 680 N/m

If a steady force of 133 N is applied when pulling the spring and elonged to a total length of 57 cm, the spring must extert the same force, but in the opposite direction, that is:

Solving for x_0

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27