What Was the Minimum Initial Kinetic Energy of a 7 kg Shot Put Thrown 18 Meters?

AI Thread Summary
To determine the minimum initial kinetic energy of a 7 kg shot put thrown 18 meters, the optimal launch angle is 45 degrees. The range equation provided, which is V0sin(2θ)/g, is incorrectly stated as it should represent time rather than distance. The correct velocity can be calculated using the formula √(R * g), where R is the range and g is the acceleration due to gravity. The discussion emphasizes the importance of correctly applying physics equations to find the energy at launch. Accurate calculations are essential for determining the shot put's initial energy.
JoeDoe
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Homework Statement



A 7 kg shot put is thrown 18 meters. What was its minimun intial energy?

Homework Equations



When θ = 45°

Range = V0sin(2θ)/g

Velocity = √(R * g)
 
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JoeDoe said:

Homework Statement



A 7 kg shot put is thrown 18 meters. What was its minimun intial energy?

Homework Equations



When θ = 45°

Range = V0sin(2θ)/g

Velocity = √(R * g)
What is the energy of the shot when launched?
Express Energy as a function of θ. When is Energy minimum?

AM
 
JoeDoe said:
Range = V0sin(2θ)/g

Check this equation.

ehild
 
Is 45 degrees the optimal angle?
 
Yes it is, but your equation for the range is wrong. Check the dimension: it is time, not length.

ehild
 

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