When you stretch a spring 20 cm past its natural length, it exerts a force of 8 N. What is the spring constant of this spring? A. 1.5 N/cm
B. 0.4 N/cm
C. 25 N/cm
D. 160 N/cm

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.

the simple machine has three main features. they are:

fulcrum is the center point or pivot point of the machine. effort is input force/ applied force. load is external force/ output.

the keisha 's machine labels are

x : load

y: fulcrum

z: lever

where is the photo and the answer choices?