A baseball with mass of 0.14 kg has an initial velocity of 38 m/s. The bat applies a force that is much larger than the weight of the ball, and the ball departs from the bat with a final velocity of 58 m/s. The contact time between the bat and the ball is 4x10^-3s. Find a. The initial and final moments of the ball
b. The impulse produced by the bat
c. The average force exerted on the ball

According to the law of conservation of mass, in a chemical reaction the total starting mass of all the reactants equal the total final mass of all the products. true or false?

Which type of bond is found between the atoms of a molecule? a. metallic b. delocalized electron c. covalent d. ionic

Aballoon is rising vertically upwards at a velocity of 10m/s. when it is at a height of 45m from the ground, a parachute bails out from it. after 3s he opens his parachute and decelerates ata a constant rate 5m/s.when. (a) what was the height of the parachutist above the ground when he opened his parachute? (b)how far is the parachutist from the balloon at t=3s? (c)with what velocity does the parachutist hit the ground? (d)after how long does the parachutist hit the ground after his exist from the balloon?