A sled is initially given a shove up a frictionless 20.0° incline. It reaches a maximum vertical height 1.60 m higher than where it started at the bottom.
Part A) What was its initial speed? Express your answer to three significant figures and include the appropriate units.

v ≈ 5.602 m/s

Explanation:

By applying Work-Energy Theorem and Principle of Energy Conservation, the physical model of given system is described below. It is assumed that height at the bottom is zero:

Where and are the kinetic energy and gravitational potential energy, respectively.

Initial velocity is found by isolating in that equation.

see earlier answer

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