A motorcyclics performing a stunt - How long is he in the air?

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The discussion revolves around a physics problem involving a motorcyclist performing a stunt by jumping over a river. The scenario includes a jump from a cliff that is 20 meters lower on one side than the other, with the motorcyclist approaching at a speed of 50 m/s and needing to clear a horizontal distance of 25 meters.

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Approaches and Questions Raised

  • Participants discuss the equations of motion relevant to the horizontal and vertical components of the jump, including the effects of gravity and initial velocity. There are attempts to derive time in the air using different formulas and methods, with some participants questioning the assumptions made in their calculations.

Discussion Status

Multiple approaches to solving the problem have been presented, with some participants offering specific equations and others providing simplified calculations. There is no explicit consensus on the correct method or outcome, and various interpretations of the problem are being explored.

Contextual Notes

Some participants note that their calculations may not account for factors such as air resistance and the angle of the jump, which could affect the actual time in the air. The discussion reflects a learning environment where assumptions and methodologies are being critically examined.

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A motorcyclist intends to perform a stunt in which he jumps a 25meter wide river.

The motorcyclist must jump from a cliff on one-side 20 meters lower than the other side.
The motorcyclist approaches the cliff at 50m/s

What formula should I use to solve for

the Horizontal direction?

And the time in the air?
 
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The horizontal direction??

What you want to do is set up the equations for distance covered with unknown angle θ and initial speed 50 m/s. The vertical acceleration is -9.8 m/s2 so the vertical speed at any t is 50 sin(θ)- 9.8t and the vertical height above the starting point is 50 sin(θ)t- 4.9t2. Since the landing side is 20 m higher than the starting side, the jump should end with
50 sin(θ)t- 4.9t2= 20. Also his horizontal distance covered is 50 cos(θ)t. In order to get across the river, he needs to have 50 cos(θ)t= 25. Solve the two equations for t and θ to answer your question.
 


To solve for the horizontal direction, you can use the formula: d = v*t, where d is the distance traveled, v is the initial velocity, and t is the time. In this case, the distance would be 25 meters and the initial velocity would be 50m/s. So, to solve for the time in the air, you would use the formula t = d/v, which would give you a time of 0.5 seconds. This means that the motorcyclist would be in the air for approximately half a second while performing the stunt. However, it's important to note that this is a simplified calculation and there are other factors that could affect the actual time in the air, such as air resistance and the angle of the jump. It's always important to take safety precautions and thoroughly plan and practice stunts like this.
 


To solve for the horizontal direction, you can use the formula: distance = velocity x time. In this case, the distance would be 25 meters and the velocity would be 50m/s. So, the formula would be 25m = 50m/s x time. Solving for time, we get a result of 0.5 seconds in the air for the horizontal direction.

To solve for the time in the air, you can use the formula: time = (final velocity - initial velocity) / acceleration. In this case, the initial velocity is 50m/s and the final velocity would be 0m/s (since the motorcyclist would reach the peak of the jump and then start to descend). The acceleration due to gravity is 9.8m/s^2. So, the formula would be time = (0m/s - 50m/s) / -9.8m/s^2. Solving for time, we get a result of approximately 5.1 seconds in the air.

However, it's important to note that these calculations are based on ideal conditions and do not take into account factors such as wind resistance and the motorcyclist's maneuvering abilities. The actual time in the air may vary. It's always important to prioritize safety and proper training when attempting stunts like this.
 

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