1.
Work (2 answers)
Correct Answer(s)
A. Transfer of energy that occurs when a force makes an object move
D. Exerting a force with your muscles.
Explanation
The correct answers for this question are "Transfer of energy that occurs when a force makes an object move" and "Exerting a force with your muscles." These answers accurately describe the concept of work. Work is the transfer of energy that occurs when a force is applied to an object and causes it to move. It can also be done by exerting a force with your muscles. Both answers capture different aspects of the definition of work.
2.
A device that makes doing work easier by increasing the force that can applied to an object or by increasing the distance over which a force can be applied by changing the direction of an applied force.
Correct Answer
D. Machine
Explanation
A machine is a device that can make doing work easier by either increasing the force applied to an object or by increasing the distance over which the force is applied. It can also change the direction of an applied force. Machines are designed to simplify tasks and make them more efficient, allowing us to accomplish tasks that would be difficult or impossible to do by hand. They can range from simple tools like levers and pulleys to complex systems like engines and computers.
3.
The force you exert is at ____ _____to the direction of the object you are moving.
Correct Answer
right angles
right angle
Explanation
When you exert a force on an object, it is applied at right angles or a right angle to the direction in which the object is being moved. This means that the force is perpendicular to the direction of motion. This is because when a force is applied at an angle other than 90 degrees, it can be resolved into two components - one parallel to the direction of motion and one perpendicular to it. However, when the force is applied at right angles, there is no parallel component and all of the force contributes to changing the direction of motion.
4.
When you do work on an object you ____ its energy.
Correct Answer
increase
Explanation
When you do work on an object, you transfer energy to it. This energy can be in the form of mechanical, electrical, or thermal energy, depending on the type of work being done. By applying a force or exerting effort, you are increasing the object's energy, either by increasing its kinetic energy (if the object is in motion) or by increasing its potential energy (if the object is at rest). Therefore, the correct answer is "increase."
5.
Ability to cause change
Correct Answer
C. Energy
Explanation
Energy is the correct answer because it is the ability to cause change or do work. In the context of the given options, work, power, and energy are all related concepts, but energy is the most general term that encompasses the others. A pulley and lever are examples of simple machines that can help to transfer or transform energy. Therefore, energy is the best answer that encompasses the ability to cause change in various forms.
6.
Amount of work done in one second
Correct Answer
C. Power
Explanation
Power is the rate at which work is done or energy is transferred or converted. It is a measure of how quickly work is being done. In the context of the given question, the amount of work done in one second can be measured by power. Power is calculated by dividing the amount of work done by the time taken to do that work. Therefore, power is the correct answer as it directly relates to the amount of work done in a given time period.
7.
Machine
Correct Answer(s)
C. A device that makes doing work easier by increasing the distance over which a force can applied by change the direction of an applied force.
E. A device that makes doing work easier by increasing the force that can be applied to an object
Explanation
The correct answer is a device that makes doing work easier by increasing the distance over which a force can be applied or by changing the direction of an applied force. This explanation aligns with the definition of a machine as a tool or device that helps to make work easier by either increasing the force that can be applied to an object or by increasing the distance over which a force can be applied.
8.
Machines make work easier by:(3 answers)
Correct Answer(s)
B. Increasing force
C. Changing the direction of an applied force
E. Increasing the distance in which a force can be applied
Explanation
Machines make work easier by increasing force because they can amplify the force applied by a person, allowing them to lift heavier objects or perform tasks that would require more force without the machine. Machines also change the direction of an applied force, such as using a pulley system to redirect the force needed to lift an object. Additionally, machines can increase the distance in which a force can be applied, such as using a lever to exert force over a larger distance.
9.
T or F? Conserving machine - energy is never conserved. Answer with T or F
Correct Answer(s)
F
Explanation
The correct answer is "F". This means that the statement "Conserving machine - energy is never conserved" is false. Energy conservation is a fundamental principle in physics, stating that energy cannot be created or destroyed, only converted from one form to another. Therefore, a conserving machine would indeed conserve energy.
10.
Mechanical advantage - the ratio of output force to ____ ______.
Correct Answer(s)
input force
Explanation
The mechanical advantage is a measure of how much a machine can amplify the input force. It is calculated by dividing the output force by the input force. In this case, the correct answer states that the mechanical advantage is the ratio of the output force to the input force, indicating that it is the input force that is being compared to the output force to determine the mechanical advantage.
11.
Mechanical advantage of a machine without friction.
Correct Answer
D. Ideal machine
Explanation
The correct answer is "ideal machine" because an ideal machine is one that has no friction, which means that all the input work is converted into output work without any energy loss. In an ideal machine, the mechanical advantage is equal to the ratio of output force to input force, making it the most efficient type of machine.
12.
A measure of how much of the work put into a machine is changed into useful output work by a machine.
Correct Answer
A. Efficiency
Explanation
Efficiency is a measure of how effectively a machine converts input work into useful output work. It indicates the percentage of input work that is actually transformed into useful output work. A higher efficiency means that a larger proportion of the input work is converted into useful output work, while a lower efficiency indicates that more of the input work is wasted or lost as heat or other forms of energy. Therefore, efficiency is a key factor in determining the performance and effectiveness of a machine.