Which of the following is a compound machine?

1 answer:

3 0

A compound machine is that which is composed of two or more simple machines. Simple machines come in 6 basic types: (1) wheel and axle, (2) inclined plane, (3) wedge, (4) pulley, (5) screw, and (6) lever. Among the choices given above, the compound machine is the can opener for it is a combination of a wedge and a lever.

You might be interested in

Which of thes is a property of a substance that is composed of atoms that are held together by ionic bonds?

Svetlanka [38]

Answer: D) It conducts electricity when it is dissolved in water

8 0

1 year ago

How many moles of Na2Cr2O7 contain 14 moles of oxygen atoms?

sergiy2304 [10]

The number of moles of sodium dichromate from the number of moles of oxygen atoms can be determined through stoichiometry. Using the molecular formula of the compound, Na2Cr2O7, 1 mole of the compound contains 7 moles of oxygen. Hence, 14 moles O2*(1 mole Na2Cr2O7/ 7 mole O2) is equal to 2 moles <span>Na2Cr2O7.</span>

7 0

3 years ago

Read 2 more answers

Arrange the molecules H2O, NH3, Ar, NaCl in order of expected increasing boiling points. 1. None of these 2. NaCl, H2O, NH3, Ar

Aleks04 [339]

Answer:

Option (4) is correct

Explanation:

NaCl is an ionic solid. $Na^{+}$ and $Cl^{-}$ ions are held together by strong coloumbic attractive force. Hence NaCl has highest boiling point'
Ar is a monoatomic molecule. Hence only weak london dispersion force exists between Ar atom/molecules. Hence it requires lowest amount of energy to boil and thereby possess lowest boiling point.
$NH_{3}$ and $H_{2}O$ are polar protic molecules. Hence they possess london dispersion force, dipole-dipole force and hydrogen bonding as intermolecular forces.
Dipole-dipole force is stronger in $H_{2}O$ than $NH_{3}$ due to more polar O-H bond than N-H bond. Also molecular weight of $H_{2}O$ is higher than $NH_{3}$ . So, more energy is required to boil $H_{2}O$ . So, $H_{2}O$ has higher boiling point than $NH_{3}$