Question

A 2.0-kg object moving at 7.0 m/s collides with an 8.0-kg object initially at rest. The...

A 2.0-kg object moving at 7.0 m/s collides with an 8.0-kg object initially at rest. The two objects stick together after the collision. If the two objects system is isolated from environment, calculate the kinetic energy change of the system after the collision.

A. -5.0J

B. -13J

C. -29J

D. -20J

E. -39J

Homework Answers

Answer #1

Mass of the first object = m1 = 2 kg

Mass of the second object = m2 = 8 kg

Initial velocity of the first object = V1 = 7 m/s

Initial velocity of the second object = V2 = 0 m/s (At rest)

Velocity of the objects after the collision = V3

By conservation of linear momentum,

m1V1 + m2V2 = (m1 + m2)V3

(2)(7) + (8)(0) = (2 + 8)V3

V3 = 1.4 m/s

Initial kinetic energy of the system = E1

E1 = 49 J

Final kinetic energy of the system = E2

E2 = 9.8 J

Change in kinetic energy of the system = E

E = -39 J

Change in kinetic energy of the system = -39 J

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A 2.0 kg object moving 5.0 m/s collides with and sticks to an 8.0 kg object...
A 2.0 kg object moving 5.0 m/s collides with and sticks to an 8.0 kg object initially at rest. a). Calculate the total momentum of the system before the collision. b). Calculate the total kinetic energy of the system before the collision. c). Calculate the kinetic energy lost by the system as a result of this collision.
A 5.0-kg mass moving at 8.0 m/s collides head-on with a 3.0-kg mass initially at rest...
A 5.0-kg mass moving at 8.0 m/s collides head-on with a 3.0-kg mass initially at rest If the collision is perfectly elastic, what is the speed of the masses just after the collision? Is the kinetic energy conserved?
a 1.5 kg car (1) initially moving at 4.0 m/s to the right collides with a...
a 1.5 kg car (1) initially moving at 4.0 m/s to the right collides with a 2.0 kg car (2) initially moving at 2.0 m/s to the left. After the inelastic collision, car 1 is moving to the left at 1.2 m/s A) What is the velocity and direction of car 2 after the collision? B) What is the change in total kinetic energy and the percentage of initial kinetic energy remaining after the collision?
A 7.0 kg block with a speed of 3.0 m/s collides with a 14.0 kg block...
A 7.0 kg block with a speed of 3.0 m/s collides with a 14.0 kg block that has a speed of 2.0 m/s in the same direction. After the collision, the 14.0 kg block is observed to be traveling in the original direction with a speed of 2.5 m/s. (a) What is the velocity of the 7.0 kg block immediately after the collision? (b) By how much does the total kinetic energy of the system of two blocks change because...
A 9.00 kg object is moving to the left with a speed 9.00 m/s. Another 9.00...
A 9.00 kg object is moving to the left with a speed 9.00 m/s. Another 9.00 object is moving to the right with a speed of 9.00 m/s. The two objects collide and stick together. The magnitude of the loss in the kinetic energy because of the collision, in Joules, is:
A 2000-kg car travelling at 50 m/s collides with an object of (your student number)-kg travelling...
A 2000-kg car travelling at 50 m/s collides with an object of (your student number)-kg travelling at 12 m/s inan opposite direction. (a) Find change in kinetic energy if both stick together and if collision is absolutely elastic. (b)Show final velocities in both cases for both objects. (c) What percentage of the original kinetic energy is this?
One object is at rest, and another is moving. The two collide in a one-dimensional, completely...
One object is at rest, and another is moving. The two collide in a one-dimensional, completely inelastic collision. In other words, they stick together after the collision and move off with a common velocity. Momentum is conserved. The speed of the object that is moving initially is 30 m/s. The masses of the two objects are 3.0 and 7.6 kg. Determine the final speed of the two-object system after the collision for the case (a) when the large-mass object is...
A 2-kg object is moving east at 9 m/s when it collides with a 8-kg object...
A 2-kg object is moving east at 9 m/s when it collides with a 8-kg object that is initially at rest. After the completely elastic collision, the larger object moves east at 1 m/s. Find the final velocity of the smaller object after the collision. (East is defined as positive. Indicate the direction with the sign of your answer.) m/s
A 2.0 kg block with a speed of 5.1 m/s collides with a 4.0 kg block...
A 2.0 kg block with a speed of 5.1 m/s collides with a 4.0 kg block that has a speed of 3.4 m/s in the same direction. After the collision, the 4.0 kg block is observed to be traveling in the original direction with a speed of 4.3 m/s. (a) What is the velocity of the 2.0 kg block immediately after the collision? (b) By how much does the total kinetic energy of the system of two blocks change because...
A 3.20-kg object is moving east at 4.50 m/s when it collides with a 6.00-kg object...
A 3.20-kg object is moving east at 4.50 m/s when it collides with a 6.00-kg object that is initially at rest. After the completely elastic collision, the larger object moves east at 3.13 m/s. 1) What is the final velocity of the smaller object after the collision? Assume that the positive direction is to the east.(Express your answer to three significant figures.)