A warehouse worker is unloading a 240. kg crate from a truck using an "ideal rope" passing over a single ideal pulley above the truck. What is the minimum horizontal frictional force that the floor must exert on the worker to keep him from slipping while slowly lifting the crate if the rope between the pulley and the man makes an angle of 25.0* with the vertical?

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."

answer: option c.

explanation:

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form