# Recent content by Ripcurl

1. ### Average Acceleration During a Collision

Homework Statement A tennis ball with a velocity of 7.97 m/s to the right is thrown perpendicularly at a wall. After striking the wall, the ball rebounds in the opposite direction with a velocity of −5.07 m/s to the left. If the ball is in contact with the wall for 0.011 s, what is the average...
2. ### Finding Mass of a Sphere

But it is. Wow. You're amazing! Thanks! XD
3. ### Finding Mass of a Sphere

So you're saying find the volume. I got 623.6145193 cm^3. Then I multiply that by the density (8.15) to get the mass. I get 5082.458333. That doesn't seem right. XD
4. ### Finding Mass of a Sphere

Homework Statement A sphere of metal has a radius of 5.3 cm and a density of 8.15 g/cm3. What is the mass of the sphere? Answer in units of g. Homework Equations Density=mass/volume Volume of a sphere=4/3лr^3 The Attempt at a Solution I found the volume by multiplying 4/3 by л and 5.3...
5. ### Finding Average Speed

Ha ha, I kinda did a double take when I saw that too, but I knew what you meant, obviously. :wink: But I got the question right! Thanks again for the help! o:)

Soh cah toa
8. ### Calc. Angle between radius vector point and positive x axis? What does that mean?

I understand that. XD That's why I asked. I wasn't expecting anyone to do anything for me. :3 Anyway, hmm, what formula? I can't say that I know. I mean, I'm thinking it has something to do with sin, but I'm not entirely sure.
9. ### Finding Average Speed

Alright, I got it! Thank you very much!
10. ### Finding Average Speed

Oh, wait, I see what you're saying. Hold on, I'll try it. One sec. :3
11. ### Calc. Angle between radius vector point and positive x axis? What does that mean?

Okay, I drew a picture and I have a graph with a circle. I have the radius as 10.38700149 and I drew an arc (representing the angle) from the the positive x axis counterclockwise to the radius in the third quadrant.
12. ### Finding Average Speed

Homework Statement A person travels by car from one city to another with different constant speeds between a pair of cities. She drives for 30.3 min at 85.2 km/h, 14.4 min at 91.1 km/h, and 48.9 min at 43.1 km/h, and spends 19.1 min eating lunch and buying gas. The distance between the initial...
13. ### Calc. Angle between radius vector point and positive x axis? What does that mean?

Here is my problem: The cartesian coordinates of a point in the xy plane are x = −8.83 m, y = −5.47 m. The distance between the point and the origin is 10.38700149. Calculate the angle  between the radius-vector of the point and the positive x axis (measured counterclockwise from the...
14. ### Calc. Angle between radius vector point and positive x axis? What does that mean?

I have this exact same problem with different numbers! (UT homework maybe? XD) I'm pretty stuck.
15. ### Urgent Tangential Speed Question

Homework Statement If the rotation of a planet of radius 5.99x10^6 m and free-fall acceleration 7.87 m/s^2 increased to the point that the centripetal acceleration was equal to the gravitational acceleration at the equator, what would be the tangential speed of a person standing at the...