Total # Posts: 17
the separation of the foci of an ellipse that describes a planet's orbit derermines A eccentricity of the orbit B period of the orbit C size of the orbit D all of the above. I think it is A because the closer the foci, the more circular versus elliptical the orbit is. ...
December 8, 2010
100 g mass is attached to a string 75 cm long. swings in a horizontal circle. The mass goes around its path once every 0.8. seconds. What is centripetal acceleration of the object? What is the tension in the string?
December 2, 2010
player kicks football from ground level with velocity of32 m/s at an angle of 40 degrees above horizontal. What is hang time of football? How far does the ball travel horizontally before hitting the ground? What is the maximum height that the ball reaches?
November 29, 2010
Find the acceleration down the ramp: skateboarder starts from rest at the top of a 12.5 m slick ramp that makes a 25 degree angle with the horizontal. (coefficient of rolling friction is negligible). Combined mass of skateboarder and skateboard = 75 kg.
November 20, 2010
Suppose an unknown substance has a melting temperature of 1,200 degrees Celsius and a density of 16.7 g/cm3. However, the different individual atoms that make up the element have very different melting temperatures and densities. The unknown substance is most likely a what?
November 19, 2010