Being the overachiever I am, i decided to take a summer course in physics to get ahead of the game... BAD IDEA. I'm really struggling with some things in this class, homework in particular. I can answer the examples in the book well, but when i am left to answer the actual questions i feel it's in another language. These are out of Physics, 7th Ed Cutnell:(adsbygoogle = window.adsbygoogle || []).push({});

1) A quarterback claims he can throw the football a horizontal distance of 183m (200yd). Furthermore, he claims that he can do this by launching the ball at 30 degrees above horizontal. Determine the speed with which he must throw the ball. Assume the ball is launched and caught at the same vertical level and ignore air resistance. For comparison, a baseball pitcher who can accuratly throw a fastball at 45 m/s (100 mph) is exceptional.

I started by drawing a diagram. I also worte out the variables as follows:

Initial V = 0 A = G = -9.8 m/s^2

V = ? X = 183 m

I then used the equation V^2 = Vo^2 + 2ax which corrisponds to:

V^2 = -4000. I took the square root of this and I came out with 63.2 m/s. Can anyone Varify?

2)Two cars A and B are traveling in the same direction, although car A is 186m behind car B. The speed of A is 24.4 m/s and the speed of B is 18.6 m/s. How much time does it take for A to catch B?

I didn't even know where to start on this question.

3)A car drive straight off a cliff that is 54m high. The police at the scene of the accident observe that the point of impact is 130m from the base of the cliff. How fast was the car travling?

Once again i don't know where to start with this equation either.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Determine the speed with which he must throw the ball

**Physics Forums | Science Articles, Homework Help, Discussion**