A ruler vibrates 70 times in 20 seconds. what is the frequency of its vibration

we know that that frequency= n/t

= 70/20

= 3.5 Hertz

Explanation:

i think that the answer

the first american roller coaster was the mauch chunk switchback railway, built in the mountains of pennsylvania in the mid-1800s. the track, originally built to send coal to a railway, was reconfigured as a "scenic tour."

hi,

what occurs during a solar eclipse?

there are small tides across earth.

the moon is between earth and the sun.

p.s. im not sure if the first answer is correct because during a solar ecliphse there are spring tides and i dont know if they are the same.