First time poster needs help with a problem at wits end

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SUMMARY

The discussion focuses on solving a physics problem involving a ski jumper's initial velocity after leaving a ramp. The jumper lands 51.8 meters horizontally with a final velocity of 20.7 m/s at an angle of 43.3 degrees below the horizontal. To determine the initial velocity, participants emphasize resolving the final velocity into horizontal and vertical components, applying trigonometric functions, and considering gravitational acceleration. The importance of establishing a coordinate system for accurate calculations is also highlighted.

PREREQUISITES
  • Understanding of vector resolution in physics
  • Familiarity with trigonometric functions (sine, cosine)
  • Knowledge of kinematic equations and gravitational acceleration
  • Ability to establish and use a coordinate system for motion analysis
NEXT STEPS
  • Study vector resolution techniques in physics
  • Learn about kinematic equations for projectile motion
  • Explore the effects of gravity on vertical motion
  • Practice problems involving trigonometric applications in physics
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This discussion is beneficial for physics students, educators, and anyone interested in understanding projectile motion and vector analysis in real-world scenarios.

Finns14
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fter leaving the end of a ski ramp, a ski jumper lands downhill at a point that is displaced 51.8 m horizontally from the end of the ramp. His velocity, just before landing, is 20.7 m/s and points in a direction 43.3 degrees below the horizontal. Neglecting air resistance and any lift that he experiences while airborne, find (a) the magnitude and (b) the direction of his initial velocity when he left the end of the ramp.

That is the problem I understand mostly how to do this problem but this is only after hours of struggling with it. I am getting frustrated that the simple math and assiging negative and positive vaule are making me unable to solve the problem.
 
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20.7 m/s and points in a direction 43.3 degrees below the horizontal
one resolves the velocity (vector) into downward (y) and horizontal (x) components. The y velocity component involves an acceleration (increase downward) due to gravity.

The x-component does not change, it is constant during the descent because there is no acceleration in the x-direction after the skier leaves the ramp.

One has the horizontal distance traveled (x=51.8 m) at vx, and the time t = vx/x
 
Welcome to PF! The first thing you need to decide is a co-ordinate system. If you use a standard x-y axis as your template, then verically up will be positive, downa will be negative and left to right movement will be positive. What you need to do first is split the velocity into vertical and horiztonal components by resolving the velocity using trig.
 

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