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A machine is something we use to help us do work. With any machine, the user must apply force to move an object. This force is called “effort”. The object being moved also has a force, called “resistance”. To move the object, the effort must be greater than the resistance. Simple machines can multiply the force put on them and change the direction of that force to easily move objects. Two common simple machines are levers and inclined planes.
A lever is a bar. To do work with a lever, one end of the bar is placed against or under an object. The user then applies force at the other end of the bar. The force can be exerted by pushing downward or lifting upward. Between the two positions is the “fulcrum”. This is the place where the force on the lever is multiplied to lift, pivot, or turn. Among other purposes, we use levers to open bottles, pump water, remove nails, and crack open nuts.
Inclined planes are angled ramps used to push heavy objects to higher places. The angle of the ramp lessens the force caused by gravity and changes the direction of the force applied to an object on it. For example, it might be necessary to lift a 200-kilogram stone into the back of a truck. To directly lift this large mass, it might take five strong men. In contrast, one man could push the stone into the truck by rolling it along a 5-meter ramp.
1/ Which of the following best states the main idea of the passage?
A. Machines are not very useful. B. Simple machines help us work more easily and quickly.
C. There are two kinds of simple machines. D. Simple machines require a lot of effort.
2/ Which of the following is closest in meaning to the word "force" as used in paragraph 1?
A. energy B. muscle C. hands D. intelligence
3/ Which of the sentences below best expresses the essential information in the underlined sentence in the passage?
Incorrect choices change the meaning in important ways or leave out essential information.
A. To move an object, the force applied must be less than the resisting force.
B. The applied force must be greater than the resisting force in order to move an object.
C. The force applied to the object is always greater than the resistance.
D. The resistance on the object must be greater than the force applied to it.
4/ From paragraph 2, we can infer that ______.
A. levers change the direction of the effort B. there are many different kinds of levers
C. levers are the best kind of simple machine D. the fulcrum is stronger than the lever
5/ In paragraph 3, the author explains the concept of inclined planes by ______.
A. including a picture B. telling a personal story C. listing facts D. using an example
A lever is a bar. To do work with a lever, one end of the bar is placed against or under an object. The user then applies force at the other end of the bar. The force can be exerted by pushing downward or lifting upward. Between the two positions is the “fulcrum”. This is the place where the force on the lever is multiplied to lift, pivot, or turn. Among other purposes, we use levers to open bottles, pump water, remove nails, and crack open nuts.
Inclined planes are angled ramps used to push heavy objects to higher places. The angle of the ramp lessens the force caused by gravity and changes the direction of the force applied to an object on it. For example, it might be necessary to lift a 200-kilogram stone into the back of a truck. To directly lift this large mass, it might take five strong men. In contrast, one man could push the stone into the truck by rolling it along a 5-meter ramp.
1/ Which of the following best states the main idea of the passage?
A. Machines are not very useful. B. Simple machines help us work more easily and quickly.
C. There are two kinds of simple machines. D. Simple machines require a lot of effort.
2/ Which of the following is closest in meaning to the word "force" as used in paragraph 1?
A. energy B. muscle C. hands D. intelligence
3/ Which of the sentences below best expresses the essential information in the underlined sentence in the passage?
Incorrect choices change the meaning in important ways or leave out essential information.
A. To move an object, the force applied must be less than the resisting force.
B. The applied force must be greater than the resisting force in order to move an object.
C. The force applied to the object is always greater than the resistance.
D. The resistance on the object must be greater than the force applied to it.
4/ From paragraph 2, we can infer that ______.
A. levers change the direction of the effort B. there are many different kinds of levers
C. levers are the best kind of simple machine D. the fulcrum is stronger than the lever
5/ In paragraph 3, the author explains the concept of inclined planes by ______.
A. including a picture B. telling a personal story C. listing facts D. using an example
