You wish to lift a 400 lb car engine a vertical distance of 3 ft using a strong rope. Unfortunately, your hand crank winch can only generate 100 lb of tension in your rope. In order to overcome this obstacle, you use a multiple pulley system (block and tackle) to lift the engine.

a)What is the mechanical advantage of this system?

b) What length of rope is required to complete the work?

Arod of some material 0.20 m long elongates 0.20 mm on heating from 21 to 120°c. determine the value of the linear coefficient of thermal expansion [in (degrees c)^-1] for this material.

Ineed ! using proper grammar, spelling, and punctuation, write at least one 5 sentence paragraph describing 3 ways we use the elements of the electromagnetic spectrum (ems) in our everyday lives.

Consider two less-than-desirable options. in the first you are driving 30 mph and crash head-on into an identical car also going 30 mph. in the second option you are driving 30 mph and crash head-on into a stationary brick wall. in neither case does your car bounce off the thing it hits, and the collision time is the same in both cases. which of these two situations would result in the greatest impact force?