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5. A 50 kg roller coaster car is launched, from ground level, at 20 m/s. The
car goes through a loop where it slows down to a speed of 12.6 m/s at.
the top of the loop. How tall is the loop?

Respuesta :

The height of the loop is 12.3 m

Explanation:

We can solve this problem by applying the principle of conservation of energy. In fact, the total mechanical energy of the car (the sum of its potential energy + its kinetic energy) must be conserved in absence of friction. So we can write:

[tex]U_i +K_i = U_f + K_f[/tex]

where :

[tex]U_i[/tex] is the initial potential energy, at the bottom

[tex]K_i[/tex] is the initial kinetic energy, at the bottom

[tex]U_f[/tex] is the final potential energy, at the top

[tex]K_f[/tex] is the final kinetic energy, at the top

We can rewrite the equation as

[tex]mgh_i + \frac{1}{2}mu^2 = mgh_f + \frac{1}{2}mv^2[/tex]

where:

m = 50 kg is the mass of the car

[tex]g=9.8 m/s^2[/tex] is the acceleration of gravity

[tex]h_i = 0[/tex] is the initial height , at ground level

u = 20 m/s is the initial speed  of the car

[tex]h_f[/tex] is the maximum height reached by the car, so the heigth of the loop

v = 12 m/s is the final speed of the car at the top of the loop

By solving the equation for [tex]h_f[/tex], we find:

[tex]\frac{1}{2}mu^2 = mgh_f + \frac{1}{2}mv^2\\h_f = \frac{u^2-v^2}{2g}=\frac{20^2-12.6^2}{2(9.8)}=12.3 m[/tex]

Learn more about kinetic energy and potential energy here:

brainly.com/question/6536722

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