Work, Power And Energy Worksheet Work And Power 1. Calculate The Work Done By A 47 N Force Pushing A Pencil 0.26 M 2. Calculate The Work Done By A 47 N Force Pushing A 0.025 Kg Pencil 0.25 M Against A Force Of 23 N. 3. Calculate The Work Done By A 2.4 N Force Pushing A 400. G Sandwich Across A Table 0.75 M Wide 4. How Far Can A Mother Push A 20.0 Kg Baby
The correct answer and explanation is:
Work and Power Worksheet
1. Calculate the Work Done by a 47 N Force Pushing a Pencil 0.26 m
To calculate the work done, we use the formula: Work=Force×Distance×cos(θ)\text{Work} = \text{Force} \times \text{Distance} \times \cos(\theta)
Since the force is applied in the direction of motion, the angle θ\theta is 0°, and cos(0∘)=1\cos(0^\circ) = 1. Work=47 N×0.26 m=12.22 J\text{Work} = 47 \, \text{N} \times 0.26 \, \text{m} = 12.22 \, \text{J}
So, the work done is 12.22 Joules.
2. Calculate the Work Done by a 47 N Force Pushing a 0.025 Kg Pencil 0.25 m Against a Force of 23 N
Here, we need to find the net force acting on the pencil. The total force acting in the direction of motion is the applied force minus the opposing force. Net Force=47 N−23 N=24 N\text{Net Force} = 47 \, \text{N} – 23 \, \text{N} = 24 \, \text{N}
Now, we can calculate the work done: Work=Net Force×Distance=24 N×0.25 m=6.0 J\text{Work} = \text{Net Force} \times \text{Distance} = 24 \, \text{N} \times 0.25 \, \text{m} = 6.0 \, \text{J}
So, the work done is 6.0 Joules.
3. Calculate the Work Done by a 2.4 N Force Pushing a 400 g Sandwich Across a Table 0.75 m Wide
First, convert the mass of the sandwich to kilograms: 400 g=0.4 kg400 \, \text{g} = 0.4 \, \text{kg}
Now, the work done can be calculated using the formula: Work=Force×Distance=2.4 N×0.75 m=1.8 J\text{Work} = \text{Force} \times \text{Distance} = 2.4 \, \text{N} \times 0.75 \, \text{m} = 1.8 \, \text{J}
So, the work done is 1.8 Joules.
4. How Far Can a Mother Push a 20.0 Kg Baby?
To solve this, we need to know the force the mother applies. However, this question is incomplete because we do not have the applied force. If we had the force, we could use the equation: Work=Force×Distance\text{Work} = \text{Force} \times \text{Distance}
To find the distance, we rearrange the equation: Distance=WorkForce\text{Distance} = \frac{\text{Work}}{\text{Force}}
Without knowing the force or work, we cannot calculate the distance.
Explanation:
Work is done when a force is applied to an object, and that object moves in the direction of the force. The basic formula to calculate work is: Work=Force×Distance×cos(θ)\text{Work} = \text{Force} \times \text{Distance} \times \cos(\theta)
where θ\theta is the angle between the force and the direction of movement. If the force is applied directly in the direction of the object’s movement, the angle is 0°, and cos(0∘)=1\cos(0^\circ) = 1, simplifying the formula to: Work=Force×Distance\text{Work} = \text{Force} \times \text{Distance}
In this worksheet, we used this formula for each scenario. The units of work are joules (J), where 1 joule is equal to 1 newton-meter (N·m).
In problem 1, we calculated the work done when a 47 N force pushes a pencil 0.26 meters. Since the force and movement are in the same direction, the work is simply the force multiplied by the distance, giving 12.22 joules.
Problem 2 involves calculating the work done against an opposing force. In this case, the net force is the applied force minus the opposing force, which results in 24 N. Multiplying this by the distance gives 6.0 joules.
Problem 3 involves pushing a sandwich across a table. With a force of 2.4 N and a distance of 0.75 m, we found that 1.8 joules of work were done.
Finally, problem 4 asks about the distance a mother can push a baby, but without information about the force applied, we cannot solve the problem.
This demonstrates how work and force are interconnected, and understanding these relationships is fundamental to analyzing physical situations in everyday life.