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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

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...
3. 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...
4. 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...
5. Formula Help?

I wasn't really sure if this counted as homework because I need them in order to solve my homework problems, but since they're not my homework I'm putting them here. I need the six projectile motion formulas. I have ∆y=Viy∆t-1/2g∆t^2 (t squared) ∆x=Vix∆t I need the other four. I'd...
6. Displacement Problem I can't figure out

Homework Statement A person walks 21m east and then walks 34m at an angle 47 degrees north of east. What is the magnitude of the total displacement? Homework Equations The Attempt at a Solution I'm not sure how you would go about finding the answer:confused: Help anyone?:tongue: