## megen505 one year ago A balloonist happens to drop his metal ballpoint pen from his balloon as he is taking notes on his flight. Because his pen has a streamlined shape, air resistance has little effect on its fall. The pen strikes the ground at 22 m/s. How high was the balloon? (Points : 6) 25 m 49 m 850 m 9,500 m

1. raane

u have to find acceleration to find height

2. raane

the formula that can be used is v^2=u^2+2as

3. raane

$$\vec v_f^2=\vec v_i^2+2\vec a \cdot \vec S$$ since $$\vec v_i=0\hat j$$,$$\vec v_f=-22\hat j$$,$$\vec a=-10\hat j$$, plug it in to get, $$(-22\hat j)^2=2(-10\hat j) \cdot \vec S$$ $$\vec S=-24.2\hat j$$ do you need further help?