Description acceptable. Assuming ideal conditions and this condition, a projectile launched at angle theta achieves a range of (read slowly) velocity squared times the sine of two theta over little g. For 10 points each:
[10h] Describe this condition that causes a term in the formula for the range of a projectile to vanish, resulting in the simplified term “sine of two theta.”
ANSWER: y nought equals zero [accept answers describing that y nought, the initial height of the projectile, is zero or there is no difference in height between the initial and final locations of the projectile; accept the ground is flat]
[10e] Under non-ideal conditions, the range is reduced by this force that arises due to air resistance and opposes the motion of objects in a fluid.
ANSWER: drag force [prompt on friction force]
[10m] The projectile spins after launch, causing this effect named for a German physicist that often appears in sports. In this effect, a rotating projectile generates lift, disrupting its trajectory.
ANSWER: Magnus effect [or Magnus force]
<Joseph Krol, Science - Physics> ~21205~ <Editor: David Bass>