100 points
you are out and about in the country and your father sees a rock that he really wants in the yard. now you must get the very heavy rock into the back of a truck. the truck bed is 3 feet off the ground. your father pulls out a 5-foot plank and begins to set up a ramp. at the same time, you (who know about mechanical advantage! ) have found a plank that is 8 feet long, and you show it to your father. which plank will give you the most mechanical advantage? calculate the ma for each plank.

On average 8 bananas make up one pound. the price is four pounds for 5.00. you must buy 25 bananas.what is your cost?

Afaulty model rocket moves in the xy-plane (the positive y direction is vertically upward). the rocket's acceleration has components ax(t) = ? t2 and ay(t) = ? ? ? t, where ? = 2.50 m/s4 , ? = 9.00 m/s2 , and ? = 1.40 m/s3 . at t = 0 the rocket is at the origin and has velocity ~v0 = v0x ? i + v0y ? j with v0x = 1.00 m/s and v0y = 7.00 m/s. (a) calculate the velocity and position vectors as functions of time. (b) what is the maximum height reached by the rocket? (c) sketch the path of the rocket. (d) what is the horizontal displacement of the rocket when it returns to y = 0?

Which stable element is used to determine the age of volcanic rock? a- argon b- carbon-14 c- potassium d- carbon-12