An asteroid is in circular orbit at an altitude of 2100 km above the surface of a planet with an orbital speed of 6.3 km/s. The minimum speed needed to escape from the surface of the planet is 11.9 km/s. The mass of the asteroid is closest to:

two charges are fixed in place on the x-axis as shown. the charge at x = 0 is negative and has magnitude q = 2 μcoulombs (1 μcoulomb = 10-6 coulombs). the charge at x = d, (d = +12 cm), is positive and has magnitude q = 4 μcoulombs. find a point x = xo along the x-axis at which the electric field is zero.

close lines strong magnet less close weaker

we need to know the time interval during which the force acts. impulse of force = momentum change