Question

1. Two objects collide and stick together. Kinetic energy

Select one:

a. unable to determine with the information.

b. Kinetic energy is conserved.

c. Kinetic energy is not conserved.

d. is conserved only if the environment is frictionless.

2. A ball of mass 0.10 kg is dropped from a height of 12 m. Its momentum when it strikes the ground is

Select one:

a. 2.4 kg·m/s.

b. 1.8 kg·m/s.

c. 1.5 kg·m/s.

d. 4.8 kg·m/s.

3. If you double the velocity of an object its

Select one:

a. both momentum and kinetic energy will double

b. kinetic energy will double

c. momentum will double

d. neither momentum nor kinetic energy will double

4. A 50-kg pitching machine (excluding the baseball) is placed on a frozen pond. The machine fires a 0.40-kg baseball with a speed of 2.3 m/s in the horizontal direction. What is the recoil speed, in m/s, of the pitching machine? (Assume negligible friction.)

Answer 1

80. ahon. Because in profantly el o a unable to determine with the informal as in perfectly elastic collision K.E. Conserved etherwise K E. not not conserved 59": - mou o Hell = Olong - dropped from height, ha igm. speed of ball at strick, vaſagh 89, momentum ! pa mua magh = 0:10 x12x 9. 81X 12 P = 115 kg. m/s / Cv 39%, 9 if we double the velocity: a momentum becomes double [pamu] 5) Kinetic energy will be. 4 times (x.E. zemu?) they ophion (e] is correct L P L V 1.6. Prva m m=0.90kg le soup 1=2.3 m/s V ve Recoil speed of machine iying, momentum conjera vation Lawr Muamo 0140x2.3 V. M ? - 50 -mly V, 0.0184 ~ 0.02 m. 10:02 m/s Vm 27879