Answer to Question #100487 in Physics for Katie

Question

Consider two rocks of different masses thrown horizontally off a building: Rock 1 has mass 2M and lands 20m away from the base of the building, while rock 2 has mass M and lands 40m away from the base. Qualitatively compare the time of flight for the rocks; compare and contrast the vertical and horizontal components of each rock.

Answer 1

The time of flight and the final vertical components of the velocity of each rock will be the same because the initial height is the same.

The horizontal component of the velocity of rock 1 is half of the velocity of rock 2:

$$\frac{v_{1x}}{v_{2x}}=\frac{\frac{d_{1}}{t}}{\frac{d_{2}}{t}}=\frac{d_{1}}{d_2}=\frac{20}{40}=0.5$$