Mechanical Energy: Solve Snowball Problem

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SUMMARY

The problem involves calculating the final speed of a 1.50 kg snowball fired from a 12.5 m high cliff with an initial velocity of 14.0 m/s at an angle of 41.0° below the horizontal. Using the principle of conservation of mechanical energy, the equation (1/2)mv^2 + mgy = constant is applied. The angle of projection does not affect the energy approach, as only kinetic and potential energy are considered. The key takeaway is that mechanical energy is conserved in the absence of external forces, allowing for straightforward calculations of final speed.

PREREQUISITES
  • Understanding of conservation of mechanical energy principles
  • Familiarity with kinetic and potential energy equations
  • Basic knowledge of projectile motion concepts
  • Ability to perform vector decomposition of velocity
NEXT STEPS
  • Study the conservation of mechanical energy in closed systems
  • Learn how to apply energy techniques to solve projectile motion problems
  • Explore the effects of initial velocity and angle on projectile trajectories
  • Investigate the relationship between potential energy and height in gravitational fields
USEFUL FOR

Students studying physics, particularly those focusing on mechanics and energy conservation, as well as educators seeking to enhance their teaching methods for energy-related problems.

norcal
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Homework Statement



A 1.50 kg snowball is fired from a cliff 12.5 m high with an initial velocity of 14.0 m/s, directed 41.0° BELOW the horizontal. Using energy techniques ONLY, find the speed of the snowball as it reaches the ground below the cliff.

Homework Equations



(1/2)mv^2+mgy=(1/2)mv^2+mgy
Kb+Ub=Kt+Ut

The Attempt at a Solution



I am not sure how to use the angle provided with either of these equations. Is there another equation that I could use?
 
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I don't think you need anything else. You could always solve it using the equations of projectile motion to see if you get the same answer.
 
If you just dropped the projectile you could easily work out its final speed because you have the height, and you know the acceleration of gravity. Firing it downward will just add some vertical velocity to the drop velocity.
 
As stated in the question I am supposed to "USE ENERGY TECHNIQUES ONLY", meaning KE and U to find the velocity but I am not sure how to do this differently here than projectile motion.
 
The angle is irrelevant for the energy approach. Choose an initial and final point for you system. Are there external forces on your system-> if not then mechanical energy is conserved. Also, where are you setting potential energy to be zero?
 

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