Acharge of +13 *10^-9 c is placed 0.25 m away from a charge of -23*10^-9 c. what will be the resultant electrical force? a. 4.3 *10^-5 c, attractive b. 4.3 *10^-5 c, repulsive c. 5.1 *10^-20 c, attractive d. 5.1 *10^-20 c, repulsive

The ozone hole appears in antarctica during

The two stars in a certain binary star system move in circular orbits. the first star, alpha, has an orbital speed of 36 km/s. the second star, beta, has an orbital speed of 12 km/s. the orbital period is 137 d. a) what is the mass of the star alpha? b) what is the mass of the star beta?

22. the top of a cliff is located a distance h above the ground. at a distance h/2 there is a branch that juts out from the side of the cliff, and on this branch a bird's nest is located. two children throw stones at the nest with the same initial speed, one stone straight downward from the top of the cliff and the other stone straight upward from the ground. in the absence of air resistance, which stone hits the nest in the least amount of time?