1.
What is any action that alters a body's state of rest; effort; pressure applied?
Correct Answer
B. Force
Explanation
Force is the correct answer because it is defined as any action that alters a body's state of rest or motion, or the pressure applied to an object. It can cause an object to move, change direction, or deform. In this context, force is the most appropriate term to describe an action that alters a body's state of rest. Friction, load, and fulcrum are not accurate descriptions of this concept.
2.
What is the resistance between two forms of the matter when they move against one another?
Correct Answer
A. Friction
Explanation
Friction is the resistance that occurs when two objects move against each other. It is caused by the interaction between the surfaces of the objects, which creates a force that opposes their relative motion. Friction can be influenced by factors such as the roughness of the surfaces and the amount of force pushing the objects together. Therefore, when two forms of matter move against each other, the resistance between them is due to friction.
3.
What produces friction?
Correct Answer
B. Two materials rubbing together
Explanation
Friction is the force that opposes the motion of two objects in contact with each other. When two materials rub against each other, the irregularities on their surfaces interlock, causing resistance and generating friction. This frictional force can result in the conversion of kinetic energy into heat energy, slowing down or stopping the objects' motion. Therefore, two materials rubbing together is the correct answer as it accurately describes the process that produces friction.
4.
Does friction make work harder or easier?
Correct Answer
A. Harder
Explanation
Friction makes work harder because it opposes the motion of objects. When two surfaces are in contact, friction acts in the opposite direction to the applied force, making it more difficult to move the objects. This resistance caused by friction requires additional force to overcome it, resulting in more work being done. Therefore, friction makes the overall task harder to accomplish.
5.
Does a rougher surface produce more or less friction?
Correct Answer
A. More
Explanation
A rougher surface produces more friction because the irregularities and bumps on the surface increase the contact area between the two objects in contact. This increased contact area results in more interlocking of the surfaces, creating more resistance to motion and therefore more friction.
6.
Friction produces
Correct Answer
B. Heat
Explanation
Friction is the force that opposes the motion of objects in contact with each other. When objects rub against each other, the friction between them causes the generation of heat. This is because the energy of motion is converted into thermal energy due to the resistance offered by friction. Therefore, the correct answer is heat.
7.
What is the support around which a lever turns called?:
Correct Answer
D. Fulcrum
Explanation
The support around which a lever turns is called the fulcrum. The fulcrum is the fixed point or pivot on which the lever rotates. It acts as a support and allows the lever to move and exert force. Without the fulcrum, the lever would not be able to function properly and achieve mechanical advantage.
8.
What is the bar that rests on the fulcrum called?
Correct Answer
B. Lever
Explanation
A lever is a simple machine consisting of a rigid bar that is supported at a fixed point called the fulcrum. When a force is applied to one end of the lever, it can be used to move or lift objects at the other end. The bar that rests on the fulcrum is called the lever, and it plays a crucial role in the functioning of this mechanical device.
9.
What does a lever do?
Correct Answer
B. Makes it easier to move an object
Explanation
A lever is a simple machine that consists of a rigid bar that rotates around a fixed point called a fulcrum. When force is applied to one end of the lever, it creates a mechanical advantage, allowing a smaller force to move a larger object. This means that a lever makes it easier to move an object by amplifying the force applied to it.
10.
What are a screw and staircase examples of?
Correct Answer
B. Inclined plane
Explanation
A screw and a staircase are both examples of an inclined plane. An inclined plane is a simple machine that consists of a flat surface that is tilted at an angle. It allows for the movement of objects from a lower height to a higher height with less force needed. In the case of a screw, it is a spiral inclined plane wrapped around a cylinder, which allows for the conversion of rotational motion into linear motion. Similarly, a staircase is a series of inclined planes that make it easier to climb or descend a height.
11.
What is the bad thing about using a lever?
Correct Answer
C. You have to move the weight a greater distance
Explanation
Using a lever requires moving the weight a greater distance, which is considered a disadvantage. This means that more effort is required to achieve the desired result compared to using other methods or tools. The increased distance can make the task more physically demanding and time-consuming.
12.
What kind of lever has the fulcrum between the load and effort?
Correct Answer
A. First class lever
Explanation
A first-class lever has the fulcrum positioned between the load and the effort. In this type of lever, the load and effort are on opposite sides of the fulcrum. When the effort is applied, it creates a rotational force around the fulcrum, allowing the load to be lifted or moved. This type of lever is commonly seen in tools like seesaws and crowbars.
13.
What kind of lever has the fulcrum at one end and the load between the fulcrum and effort?
Correct Answer
B. Second class lever
Explanation
A second class lever has the fulcrum at one end and the load between the fulcrum and effort. In this type of lever, the effort is applied on one side of the fulcrum while the load is on the other side, with the fulcrum acting as the pivot point. This lever configuration allows for the multiplication of force, as the effort arm is longer than the load arm. Examples of second class levers include a wheelbarrow and a nutcracker.
14.
A wheelbarrow and bottle opener are examples of?
Correct Answer
B. Second class lever
Explanation
A second class lever is a type of lever where the load is located between the effort (force) and the fulcrum (pivot point). In the case of a wheelbarrow, the load (the weight being carried) is placed in the bucket, the effort is applied by pushing down on the handles, and the fulcrum is the wheel. Similarly, a bottle opener works as a second class lever because the bottle cap acts as the load, the effort is applied by pushing down on the handle, and the fulcrum is the edge of the bottle cap.
15.
A hammer, fishing rod and tweezers are examples of
Correct Answer
C. Third class lever
Explanation
A hammer, fishing rod, and tweezers are examples of third class levers because in a third class lever, the effort is applied between the fulcrum and the load. In these examples, the fulcrum is the pivot point or the point where the tool is held or supported, the effort is applied by the hand or arm, and the load is the object being manipulated or lifted. The effort is closer to the fulcrum than the load, which allows for greater speed and range of motion, but less force.
16.
When the fulcrum is at one end and the effort is between the load and fulcrum
Correct Answer
C. Third class lever
Explanation
A third class lever is characterized by having the fulcrum at one end, the effort in the middle, and the load at the other end. In this configuration, the effort is applied closer to the fulcrum than the load, resulting in a mechanical advantage less than 1. Third class levers are commonly found in the human body, such as when we flex our biceps to lift a dumbbell. The effort is exerted by the biceps, the fulcrum is the elbow joint, and the load is the weight of the dumbbell.
17.
A seesaw, balance scale, and pliers are examples of
Correct Answer
A. First class lever
Explanation
A first class lever is a type of lever where the fulcrum is located between the effort and the load. In the case of a seesaw, balance scale, and pliers, the fulcrum is the pivot point, the effort is applied at one end, and the load is at the other end. When a force is applied to one side, it causes the other side to move in the opposite direction. This is the characteristic of a first class lever, making it the correct answer in this case.
18.
What is another named for an inclined plane?
Correct Answer
B. Ramp
Explanation
An inclined plane is another term for a ramp. It is a simple machine that is often used to move heavy objects to a higher or lower level with less force. The slope of the ramp reduces the amount of force required to move the object, making it easier to transport. Therefore, the correct answer is "ramp".
19.
What lifts or lowers the objects along a slope using the least amount of force?
Correct Answer
B. Inclined plane
Explanation
An inclined plane is a simple machine that allows objects to be lifted or lowered along a slope with the least amount of force. The inclined plane reduces the amount of force required by spreading it out over a longer distance. By increasing the distance over which the force is applied, the inclined plane makes it easier to move objects up or down a slope with minimal effort.
20.
What machine raises an object or splits it apart?
Correct Answer
C. Wedge
Explanation
A wedge is a simple machine that is designed to raise or split objects apart. It consists of a sharp, pointed edge that is thick at one end and tapers to a thin edge at the other. When a wedge is driven into an object, it applies a force that pushes the object apart, allowing it to be raised or split. This makes the wedge the correct answer to the question.
21.
Which machine uses less force to move the object, but takes a greater distance to move it?
Correct Answer
B. Inclined plane
Explanation
An inclined plane requires less force to move an object compared to other machines, but it takes a greater distance to move the object. This is because the inclined plane allows the force to be spread out over a longer distance, reducing the amount of force needed. The trade-off is that the object needs to be moved along a longer path to reach the desired destination.
22.
What machine is made of two wheels and moves heavy weights by reducing friction?
Correct Answer
D. Wheel and axle
Explanation
The wheel and axle is a simple machine that consists of a wheel attached to an axle. This machine is designed to reduce friction and make it easier to move heavy weights. The wheel and axle work together to distribute the weight evenly and allow for smooth movement. By rotating the wheel, the axle turns and helps to move the heavy load with less effort. This makes the wheel and axle an effective tool for transportation and lifting heavy objects.
23.
What are wheels with teeth called?
Correct Answer
B. Gear
Explanation
Wheels with teeth are called gears. Gears are mechanical devices that transmit motion and torque from one part of a machine to another. They are commonly used in machinery and vehicles to control speed, direction, and force. Gears can be found in various sizes and configurations, and they are essential components in many mechanical systems.
24.
Where can you find gears?
Correct Answer
B. Bike, can opener, egg beater
Explanation
Gears can be found in a bike, can opener, and egg beater. These objects use gears to transfer and transmit motion, allowing them to perform their specific functions. In a bike, gears are used to change the speed and power of pedaling. A can opener uses gears to rotate and puncture the can lid. An egg beater uses gears to rotate the beaters and mix ingredients. These examples demonstrate the practical applications of gears in various everyday objects.
25.
What do elevators, flag poles, and window blinds use?
Correct Answer
B. Pulley
Explanation
Elevators, flag poles, and window blinds use pulleys. Pulleys are simple machines that consist of a wheel with a groove and a rope or cable that runs along the groove. When a force is applied to one end of the rope, the pulley helps to distribute and redirect the force, making it easier to lift or lower heavy objects. In the case of elevators, pulleys are used to lift the elevator car up and down. Flag poles often use pulleys to raise and lower flags, and window blinds use pulleys to adjust the position of the blinds.
26.
What do doorknobs, roller skates, and wagons use?
Correct Answer
C. Wheel and axle
Explanation
Doorknobs, roller skates, and wagons all use the wheel and axle mechanism. This mechanism consists of a wheel attached to an axle, allowing the wheel to rotate around the axle. This design enables smooth and efficient movement by reducing friction between the object and the surface it moves on. The wheel and axle mechanism is commonly used in various applications, including these examples mentioned.
27.
A smaller gear moves
Correct Answer
A. Faster
Explanation
A smaller gear moves faster because it has fewer teeth than a larger gear. As the gear rotates, each tooth pushes against another tooth, causing the gear to move. With fewer teeth, the smaller gear covers less distance in each rotation compared to the larger gear. Therefore, the smaller gear needs to rotate faster in order to cover the same distance in the same amount of time.
28.
When one gear moves clockwise the other moves
Correct Answer
B. Counterclockwise
Explanation
When one gear moves clockwise, the other gear moves in the opposite direction, which is counterclockwise. This is because gears are designed to mesh with each other in a way that their teeth interlock and transfer motion. The direction of rotation is determined by the shape and positioning of the gear teeth. In this case, the gears are set up in such a way that when one gear rotates in a clockwise direction, the other gear rotates in the opposite direction, counterclockwise.
29.
What is a wheel with a grooved rim in which a rope moves to change directions with less force?
Correct Answer
D. Pulley
Explanation
A pulley is a wheel with a grooved rim that allows a rope or cable to move in the groove. It is used to change the direction of the force applied to the rope with less effort. By wrapping the rope around the pulley, the force required to lift or move an object can be reduced. This makes it easier to lift heavy objects or change the direction of a force, such as in a flagpole or a crane.