Work Done: Understanding Force and Movement
Work is said to be done when a force is applied to an object and the object moves in the direction of the force. It’s a fundamental concept in physics that links force and energy through movement.
Theory for Class 9 Science
In this activity:
- A car pulls a cube with a rope.
- As the car moves forward, it applies a pulling force on the cube.
- If this force overcomes friction, the cube starts moving.
- Since the force and motion are in the same direction, positive work is done.
Work Done Formula:
W = F × d × cos(θ)
- F = Force applied
- d = Displacement
- θ = Angle between force and direction of motion
In this case, θ = 0°, so cos(0) = 1, and the formula simplifies to:
W = F × d
Also, force can be calculated using Newton’s Second Law:
F = m × a
(where m is mass and a is acceleration)
Real-Life Applications
- Pulling a loaded cart on a road.
- Lifting a bag using a pulley or rope.
- Industrial machines moving materials on conveyors.
- Vehicles towing broken-down cars.
Observations from the Experiment
- More force = more work
- More distance = more work
- No movement = zero work, even if force is applied
- Work is done only when there is displacement in the direction of the force
Summary Table
| Parameter | Change | Effect on Work |
|---|---|---|
| Force | Increase | Work increases |
| Force | Decrease | Work decreases |
| Displacement | Increase | Work increases |
| Displacement | Zero | Work becomes zero |
Visualize Work in Action with Dencity
With the Dencity virtual lab, students can:
- Simulate a car pulling a cube.
- Adjust force and distance.
- Observe how work increases or becomes zero based on movement.
- Explore real-time calculations of W = F × d.
This activity is part of the Class 9 Science syllabus and is available on Android, iOS, and desktop via the Dencity app.
Dencity for Teachers
Dencity makes interactive teaching more effective:
- Live simulations of work and energy.
- Assign tasks with automatic feedback and grading.
- Teach using real-time diagrams and force vectors.
- Monitor student understanding through analytics dashboards.
Optimized for Touch-Based Smart Panels
Students can drag the car, adjust mass and force, and watch the cube move—all through intuitive touch gestures. Great for smart classrooms with interactive panels.
Request a Demo or Custom Plan
Ready to teach physics through hands-on virtual experiments? Contact us today for a free demo and get custom pricing for your school or institution.
Frequently Asked Questions
- When is work considered done?
When a force causes an object to move in the same direction as the force. - What if the object doesn’t move?
Work done is zero, even if force is applied. - What units are used for work?
Joules (J). - What increases work?
Greater force or more distance. - Can I simulate this in Dencity?
Yes, with real-time visuals and interactive control. - Which class covers this topic?
This is part of the Class 9 Science curriculum. - Does Dencity support auto-evaluation?
Yes, including student performance tracking. - Can I assign this as homework?
Absolutely—with full virtual lab access. - Does Dencity work on tablets and phones?
Yes, on Android, iOS, and desktop. - How do we get started with Dencity?
Contact us for a demo and custom integration support.
