Primaria Catapulta

[Xiomy]

A catapult on a cliff launches a large round rock towards a ship on the ocean below. The rock leaves the catapult from a height H of 32.0 m above sea level, directed at an angle θ above the horizontal with an unknown speed v0.

The projectile remains in flight for 6.00 seconds and travels a horizontal distance D of 158.0 m. Assuming that air friction can be neglected, calculate the value of the angle θ.


Calculate the speed at which the rock is launched.



To what height above sea level does the rock rise?

[Jose D. Escobedo]

Re: Catapulta

It's parabolic motion.

$\displaystyle y- h = v_o t\sin \theta - \frac{g}{2} t^2$...(1)

$\displaystyle v_o \cos \theta =\frac{x}{t}$ ...(2)

$y=0$ because it is at sea level, in other words you have a two-system equation with two unknowns $v_o$ and $\theta$

Once, you've got $\theta$ and $v_o$ to calculate the maximum height $y_{max}$apply the following expression.

$\displaystyle y_{max}-h = \frac{v^2 \sin^2 \theta}{2g}$

I hope that helps.

regards

Jose.

[Xiomy]

Re: Catapulta

Muchas gracias, me ha servido de mucho.