Urgent: when a bat hits a ball, the impulse is

a)the change in velocity multiplied by force*
b) the mass multiplied by force
c) the mass multiplied by acceleration
d) the force multiplied by the time the objects are in contact

*i think it's a

What is the gravitational attraction between a dating couple whose centers of mass are 0.630 m apart if the boy weighs 715 n and the girl weighs 465 n?

Two cannon balls weighing 18 kg and 24 kg are chained together and fired horizontally with a velocity of 165 m/s from the top of a 21-m wall. the chain breaks during the flight of the cannonballs and the 18-kg cannonball strikes the ground at t = 1.5 s, at a distance of 240 m from the foot of the wall, and 7 m to the right of the line of fire. determine the position of the other cannonball at that instant. neglect the resistance of the air.

An alarm clock has a current of 4.5 amps and a resistance of 3.2 ohms. what is the voltage in the circuit? a.1.4 volts b.0.71 volts c.14 volts d.46 volts