Describe the relationship 18 What is a lever? On which principle does it work?
Is velocity ratio of a machine affected by applying

A lever is a bar that turns on an unmoving point called a fulcrum. When you push or pull on one end of the bar that pressure is called the force. The object that is lifted on the other end is called the load.

Step-by-step explanation:

Let a machine overcome a load L by the application of an effort E. In time t, let the displacement of effort of dE ad the displacement of load be dL.

Work input =Effort× displacement of effort

=E×dE

Work output =Load× displacement of load

=L×dL

Efficiency=Work inputWork output

=E×dEL×dL=EL×dEdL

=EL×dE/dL1

But Effort(E)Load(L)=M.A.

and dLdE=V.R.

∴Efficiency η=V.R.M.A. or M.A.=V.R.×η

Thus, the mechanical advantage of a machine is equal to the product of its efficiency and Velocity Ratio.

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations:

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons