Physics and the movement of boats – problem solving exercises
|
|
Physics |
|
Lesson plan #2 |
|
ABOUT THE LESSON |
|
|
Topic |
Physics and the movement of boats – problem solving exercises |
|
Duration |
1 hour (45 min) |
|
Assumed prior knowledge |
Concepts studied with respect of the 2nd Principle of Mechanics: velocity, relative velocity, acceleration, inertial force, mechanical impulse (Lesson no. 1). |
|
Goal(s) of the lesson |
|
|
The big idea behind the topic |
|
|
Results of the lesson |
Solving simple problems, related to the movement of boats, by applying laws of uniformly varied motion and the 2nd Principle of Mechanics formulas, based on mathematical calculation literacy. |
|
Competencies |
|
|
Methods |
|
|
Relevance to the curriculum |
|
|
Stakeholder involvement |
|
|
EQUIPMENT AND MATERIALS NEEDED |
For 1 team of 5 students |
||||||||
This is a recommended list: Observations
|
|
STEP-BY-STEP ACTIVITIES |
|
|
Step 1 (2 min) |
Organizational moment (checking presence, capturing attention, preparing didactic materials, etc.) |
|
Step 2 (10 min) |
|
|
Step 3 (25 min) |
|
|
Step 4 (5 min) |
|
|
Step 5 (3 min) |
Conclusions:
|
|
Assessment |
|
|
Useful links |
|
WORKSHEET
Problems referring to the relative movement of boats on a river
On a river that flows at a constant velocity, Vw = 3 m/s, there is a motor boat that can move at a velocity of 9 m/s relative to the water.
- For general school and high school students
Statement:
The boat has to travel a distance of 100 m between two trees, A and B, located on the same side of the river. When moving along the river, the boat is oriented parallel to the velocity of the water flow. It is considered that the observer is on the shore, at a fixed point, close to the tree A, and the direction of the water flow is from A to B in relation to this observer.
Notations:
- Va – the water flow velocity vector relative to the shore
- Vb – the velocity vector of the boat with the engine running against the water
Calculate:
- The time in which the boat covers the distance from A to B with the engine off.
- The time in which the boat covers the distance from A to B with the engine running.
- The time in which the boat covers the distance from B to A with the engine running.
- The time in which the boat travels the way back A-B-A with the engine running.
- For high school students:
Statement:
The boat has to cross the river, which is 10 m wide to the opposite bank. It is considered that on the opposite bank there is a tree C, located in a way that AC is perpendicular to AB. When crossing the river, the boat is oriented perpendicular to the velocity of the water flow.
Notation:
- Vr – the relative velocity vector of the boat
Calculate:
- The time required for the boat to cross the river from A to M (located on the opposite bank) with the engine running.
- Distance CM on which the boat moves, carried by the current, downstream from point C.

Erasmus+ Cooperation partnerships project
Sailing Into Opportunities
No. 2023-1-LT01-KA220-SCH-000161306
Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the National Agency. Neither the European Union nor National Agency can be held responsible for them.

