contestada

An object rolls off a tabletop with a horizontal velocity v0x = 2.2 m/s. The table is at a height y0 = 0.65 m, above the floor. Use a coordinate system with its origin on the floor directly beneath the point where the object rolls off the table, its horizontal x-axis lying directly beneath the object’s trajectory, and its vertical y-axis pointing up.
Find the angle of impact, in degrees below the horizontal.

Respuesta :

Answer:

58.6 degrees below the horizontal

Explanation:

The horizontal velocity of the object remains constant:

[tex]v_x = 2.2 m/s[/tex]

The vertical motion instead is an accelerated motion, so the vertical velocity changes according to

[tex]v_y ^2 - u_y^2 = 2gd[/tex]

where

[tex]v_y[/tex] is the final vertical velocity

[tex]u_y = 0[/tex] is the initial vertical velocity

g = -9.8 m/s^2 is the acceleration of gravity (downward, so with a negative sign)

d = -0.65 m is the vertical displacement of the object

Solving the equation for [tex]v_y[/tex],

[tex]v_y = \sqrt{u_y^2 +2gd}=\sqrt{0+2(-9.8 m/s^2)(-0.65 m)}=3.6 m/s[/tex]

The vertical velocity just before the impact is therefore -3.6 m/s (negative since it points downward).

The angle of impact below the horizontal therefore will be

[tex]\theta=tan^{-1} (\frac{v_y}{v_x})=tan^{-1} (\frac{3.6 m/s}{2.2 m/s})=58.6^{\circ}[/tex]

below the horizontal.