1.
If a force moves an object or changes its direction, what is being done?
Correct Answer
A. Work
Explanation
When a force moves an object or changes its direction, work is being done. Work is defined as the transfer of energy that occurs when a force is applied to an object and the object is displaced in the direction of the force. In this scenario, the force is causing the object to move or change its direction, which requires the application of energy and therefore constitutes work.
2.
The unit used to measure Work is:
Correct Answer
D. Joule
Explanation
The unit used to measure work is the joule. Work is defined as the amount of energy transferred by a force acting through a distance. The joule is a derived unit of energy in the International System of Units (SI), and it is equal to the work done by a one newton force acting over a one-meter distance. It is commonly used to measure work, energy, and heat.
3.
The operation used for calculating Work is:
Correct Answer
B. Multiplication
Explanation
The operation used for calculating work is multiplication. This is because work is calculated by multiplying the force applied to an object by the distance over which the force is applied. This formula, Work = Force x Distance, shows that multiplication is the correct operation to use.
4.
Who does more work - a man who lifts a large box from the ground up into the back of a truck, or a man who puts the same box on a trolley and wheels it up a ramp into the truck?
Correct Answer
C. Both of them do the same work
Explanation
Both of them do the same work because work is defined as the product of force and displacement. In this case, both men are exerting a force to move the box a certain distance. The only difference is the method they use to move the box, but the work done is the same in both cases.
5.
A weightlifter lifts barbells of 200 Newtons above his head to a height of 2 meters. How much work does he do?
Correct Answer
D. 400 N-m
Explanation
The work done by the weightlifter can be calculated using the formula: Work = Force x Distance. In this case, the force exerted by the weightlifter is 200 Newtons and the distance over which the force is exerted is 2 meters. Therefore, the work done is 200 N x 2 m = 400 N-m.
6.
Energy and work use the same unit of the Joule because:
Correct Answer
B. Energy is required to do work
Explanation
Energy and work use the same unit of the Joule because energy is required to do work. Work is defined as the transfer of energy from one object to another, or the application of a force over a distance. The amount of work done is equal to the amount of energy transferred. Therefore, it makes sense for both energy and work to be measured in the same unit, the Joule.
7.
One joule is equal to:
Correct Answer
A. 1 N-m
Explanation
One joule is equal to 1 N-m because joule is the unit of energy or work done, and work done is calculated by multiplying the force applied to an object by the distance it moves in the direction of the force. Here, N represents the unit of force (Newton) and m represents the unit of distance (meter), so multiplying them gives the unit of work or energy, which is joule.
8.
Aside from the work being done, what other factor shall be considered in determining the power?
Correct Answer
A. Distance
Explanation
In addition to the work done, distance should also be considered in determining power. Distance is a crucial factor because it indicates the amount of space covered during the work. Power is defined as the rate at which work is done or the amount of work done per unit of time. Therefore, the distance traveled plays a significant role in determining how quickly the work is completed, and ultimately affects the power exerted.
9.
The rate at which work is done is called ____________ .
Correct Answer
C. Power
Explanation
Power is the rate at which work is done. It is a measure of how quickly work is being done or how quickly energy is being transferred. Power is calculated by dividing the amount of work done by the time taken to do the work. It is usually measured in watts (W) or horsepower (hp). Therefore, power is the correct answer to the given question.
10.
Power is measured in:
Correct Answer
C. Watt
Explanation
Power is a measure of the rate at which work is done or energy is transferred. It is calculated by dividing the amount of work done or energy transferred by the time taken. The unit of power is the watt, which is equal to one joule per second. Therefore, the correct answer is watt.
11.
The old imperial unit for power is:
Correct Answer
C. Horsepower
Explanation
The old imperial unit for power is horsepower. Horsepower is a unit of measurement that was commonly used to measure the power output of engines, particularly in the early days of the automotive industry. It is still used today in some contexts, such as measuring the power of large engines or in the horse racing industry. However, the watt is the standard unit for power in the International System of Units (SI).
12.
If a weightlifter lifts 2000 Newtons to a height of 2 meters in 4 seconds, how powerful is he?
Correct Answer
B. 1000 J/s
Explanation
The correct answer is 1000 J/s because power is calculated by dividing the work done by the time taken. In this case, the work done is the product of the force applied (2000 N) and the distance moved (2 m), which is 4000 J. Dividing this by the time taken (4 s) gives a power of 1000 J/s.
13.
To say that work is scientifically done, the force must make the object _________.
Correct Answer
B. Change position
Explanation
In order for work to be scientifically done, the force applied to the object must cause it to change position. This is because work is defined as the transfer of energy that occurs when a force is applied to an object and causes it to move in the direction of the force. Therefore, if the object does not change position, no work is being done.
14.
A man exerts a force of 60 N to a table which causes it to move by 2.5 meters. What was the work done?
Correct Answer
C. 150 J
Explanation
The work done is calculated by multiplying the force applied to an object by the distance it moves in the direction of the force. In this case, the man exerts a force of 60 N and the table moves 2.5 meters. Therefore, the work done is 60 N * 2.5 m = 150 N-m.
15.
What power is required for a person to do a 780 J in 45 s?
Correct Answer
B. 17.33 W
Explanation
The power required for a person to do work is calculated by dividing the amount of work done by the time taken. In this case, the person does 780 J of work in 45 s. Dividing 780 J by 45 s gives a power of 17.33 W.
16.
Suppose a box is lifted with a force of 97 N to a height of 5 meters, what could be the power used?
Correct Answer
D. Cannot be determined
Explanation
The power used to lift the box cannot be determined based on the given information. Power is the rate at which work is done, and work is defined as the product of force and distance. In this case, we know the force (97 N) and the distance (5 meters), but we do not know the time it took to lift the box. Since power is calculated as work divided by time, without knowing the time, we cannot determine the power used.
17.
What is the force applied if the work done on a push cart is 350 J that covered a distance of 22 meters?
Correct Answer
A. 15.91 N
Explanation
The force applied can be calculated using the formula: force = work done / distance. In this case, the work done is given as 350 J and the distance covered is 22 meters. Plugging these values into the formula, we get force = 350 J / 22 m = 15.91 N. Therefore, the correct answer is 15.91 N.
18.
In what month is the annual Earth Day celebrated?
Correct Answer
D. April
Explanation
Earth Day is celebrated annually on the month of April. This day is dedicated to raising awareness about environmental issues and promoting actions to protect the Earth. It serves as a reminder for individuals and communities to take responsibility for the planet and make sustainable choices. Celebrated worldwide, Earth Day brings people together to participate in various activities such as tree planting, clean-up campaigns, and educational events to promote a healthier and more sustainable environment.