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2.1 A car with a weight of 10 000 N is travelling eastwards on a level road, while the engine is applying a force, F, eastwards - NSC Technical Sciences - Question 2 - 2022 - Paper 1
Question 2
2.1 A car with a weight of 10 000 N is travelling eastwards on a level road, while the engine is applying a force, F, eastwards. The car experiences air resistance o... show full transcript
Worked Solution & Example Answer:2.1 A car with a weight of 10 000 N is travelling eastwards on a level road, while the engine is applying a force, F, eastwards - NSC Technical Sciences - Question 2 - 2022 - Paper 1
Step 1
2.1 Draw a free-body diagram for this situation.
Answer
To draw a free-body diagram of the situation, consider the forces acting on the car:
- Weight (W): Acting downwards with a magnitude of 10,000 N.
- Normal Force (N): Acting upwards with a value equal to the weight, also 10,000 N.
- Applied Force (F): The force exerted by the engine, acting eastwards, indicating that it is greater than 0 N.
- Air Resistance (F_air): Acting westwards with a magnitude of 2,500 N, opposing the direction of motion.
- Friction (F_friction): Acting westwards with a magnitude of 500 N, also opposing the forward motion.
All forces should be represented as arrows with correct directions and magnitudes labeled.
Step 2
2.2 Name and define the property of a body that causes whiplash.
Answer
The property that causes whiplash is called inertia.
Definition: Inertia is the tendency of an object to resist changes in its state of motion. In the context of a rear-end collision, when the car suddenly accelerates forward, the neck and head may lag behind due to their inertia, leading to a rapid movement that can result in injury.
Step 3
Step 4
2.3.2 Calculate the acceleration of the canoe.
Answer
To calculate the acceleration of the canoe, we first determine the net force acting on it:
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The net force, ( F_{net} ), can be calculated by: [ F_{net} = (F_A + F_B) - F_{water} ] [ F_{net} = (50 N + 55 N) - 18 N ] [ F_{net} = 87 N ]
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Using Newton's second law, we can calculate the total mass of the system: [ m_{total} = m_{A} + m_{B} + m_{canoe} = 60 kg + 65 kg + 20 kg = 145 kg ]
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Now, applying the formula for acceleration: [ a = \frac{F_{net}}{m_{total}} = \frac{87 N}{145 kg} \approx 0.60 m.s^{-2} ]
Step 5
2.3.3 Calculate the resultant force that is needed to increase the velocity of the canoe to 5 m.s⁻¹ in 6 seconds.
Answer
To calculate the resultant force needed:
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First, determine the change in velocity: [ \Delta v = v_{final} - v_{initial} = 5 m.s^{-1} - 3 m.s^{-1} = 2 m.s^{-1} ]
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Next, calculate the acceleration needed for this change over 6 seconds: [ a = \frac{\Delta v}{\Delta t} = \frac{2 m.s^{-1}}{6 s} \approx 0.33 m.s^{-2} ]
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Now we can find the new resultant force: [ F_{net} = m_{total} \cdot a = 145 kg \cdot 0.33 m.s^{-2} \approx 48 N ]
This is the resultant force already provided by the applicants. The additional force required over existing forces can be calculated considering the balance of forces in the direction of desired motion.