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# Someone explain this to me? watch

1. Its 13)c and 16)c I don't quite get.
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2. For 13c, can you recall the equation that links area to flow? Use that.

For 16c it's really just a sum of forces. The work the horse is doing that which is required to move the boat horizontally, so ideally the horse wants to be directly infront of the boat so that the tension in the rope = force required to pull the boat. If it's off to the side the tension in the rope is going to be greater since there's a now a vertical component of force. The longer the rope is, the smaller this vertical component and hence a lower tension in the rope.
3. (Original post by Oliver.Farren)
For 13c, can you recall the equation that links area to flow? Use that.

For 16c it's really just a sum of forces. The work the horse is doing that which is required to move the boat horizontally, so ideally the horse wants to be directly infront of the boat so that the tension in the rope = force required to pull the boat. If it's off to the side the tension in the rope is going to be greater since there's a now a vertical component of force. The longer the rope is, the smaller this vertical component and hence a lower tension in the rope.
Thx for that explanation cleared doubts in my head .
And I'm not too sure what you mean by the 'equation that links area to flow'

This is what to the marks schemes says for 13Ci)
Explain how this would increase the range of the ball.
(smaller area of turbulent flow 􀃆) less resistive force (1)
Less kinetic energy dissipated / kinetic energy dissipated at lower
rate / less work done against air resistance / less deceleration (1)
4. (Original post by 123formyabc)
Thx for that explanation cleared doubts in my head .
And I'm not too sure what you mean by the 'equation that links area to flow'

This is what to the marks schemes says for 13Ci)
Explain how this would increase the range of the ball.
(smaller area of turbulent flow 􀃆) less resistive force (1)
Less kinetic energy dissipated / kinetic energy dissipated at lower
rate / less work done against air resistance / less deceleration (1)
The turbulent flow causes a resistance, So decreasing the amount of turbulent flow will decrease the deceleration so the ball will go further.
5. A longer rope would result in a smaller angle formed between the direction of the boat's motion and the rope, meaning the horse needn't pull as hard to give the boat the same constant velocity.
6. (Original post by hello calum)
The turbulent flow causes a resistance, So decreasing the amount of turbulent flow will decrease the deceleration so the ball will go further.
Yeah that makes more sense thx

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