Question 2.2. A book is given a sudden push to make it slide along a desktop. If the initial speed of the slide is doubled, by what factor is the distance that the book slides changed?
(Points : 1)
0.5
0.25
2.0
4.0
Question 3.3. A 720 kg roller-coaster car starts off from Location A. Assuming friction does not impede the car's motion, what will be the change in its potential energy by moving from Location A to Location B?
(Points : 1)
7.1 × 103 J
6.1 × 104 J
6.0 × 105 J
7.8 × 105 J
Question 4.4. A 20 kg cart is moving at 2.0 m/s when a 5.0 N force is applied for a distance of 6.0 m in the direction the car is moving. What is the kinetic energy of the cart at the end of the 6.0 m?
(Points : 1)
40 J
70 J
10 J
30 J
Question 5.5. A 0.145 kg baseball is thrown from a platform above the ground at a 10 m/s. The ball is moving 15 m/s when it strikes the ground. From what height above the ground was the ball thrown?
(Points : 1)
6 m
10 m
5 m
1 m
Question 6.6. An extremely elastic ball loses only 20 percent of its kinetic energy in a bounce. If such a ball were dropped from a height of 5.0 m, how high would the ball bounce?
(Points : 1)
1.0 m
2.0 m
4.0 m
5.0 m
Im trying to figure these out as well
Which of these is true about mechanical energy?
- mechanical energy sometimes changes into thermal energy
A book is given a sudden push to make it slide along a desktop if the initial speed of the slide is doubled by what factor is the distance that the book slides changed?
- 4.0
A 720 kg roller coaster car starts off from location A Assuming friction does not impede the car's motion..
- 6.0 x 10^5 J
3.04 Quiz Conservation of energy 2
Continuing****
4. 70 J
5. 6 m
6. 4.0 m
*** remember different versions may change answers but these are right
Thanks
To solve questions 2.2, 3.3, 4.4, 5.5, and 6.6, we need to use principles of physics. Let's go through each question one by one.
Question 2.2: The question asks how the distance that the book slides changes when the initial speed is doubled. To answer this, we can use the equation of motion for constant acceleration, which is distance = (initial speed * time) + (0.5 * acceleration * time^2). In this case, acceleration is constant, so it does not change. If we double the initial speed, the distance formula becomes distance = (2 * initial speed * time) + (0.5 * acceleration * time^2). We can see that the distance is directly proportional to the initial speed, so if the initial speed is doubled, the distance will also be doubled. Therefore, the factor by which the distance changes is 2.0.
Question 3.3: The question asks about the change in potential energy when a roller-coaster car moves from one location to another without friction. The potential energy is given by the equation potential energy = mass * gravity * height. In this case, the mass of the car and the acceleration due to gravity do not change. Therefore, the change in potential energy depends only on the change in height. Without more information about the specific heights of Location A and Location B, we cannot determine the exact change in potential energy. Therefore, we need more information to answer this question.
Question 4.4: This question requires calculating the kinetic energy of a cart after a certain distance is covered with a known force. The formula for kinetic energy is given by kinetic energy = 0.5 * mass * velocity^2. In this case, the mass of the cart is given and the initial velocity is also given. We need to find the final velocity. We can use the equation of motion: final velocity^2 = (initial velocity^2) + (2 * acceleration * distance). Here, the acceleration is given by the force divided by the mass. Plugging in the values and solving for the final velocity, we can then substitute the final velocity in the kinetic energy formula to find the answer. The correct answer is 70 J.
Question 5.5: This question requires finding the height from which a baseball was thrown given the initial and final velocities. We can use the principle of conservation of energy. The initial energy is given by the potential energy at the starting height, which is m * g * h, where m is the mass of the baseball, g is the acceleration due to gravity, and h is the starting height. The final energy is given by the kinetic energy at the striking velocity, which is 0.5 * m * v^2, where v is the striking velocity. Equating the initial and final energies and solving for h, we can find the answer. The correct answer is 6 m.
Question 6.6: This question involves a bouncing ball and the percentage of kinetic energy it loses after each bounce. To solve this question, we can use the principle of conservation of energy. The initial energy is given by the potential energy at the drop height, which is m * g * h, where m is the mass of the ball, g is the acceleration due to gravity, and h is the drop height. The final energy is given by the potential energy at the bounce height, which is m * g * H, where H is the bounce height. As the ball loses 20 percent of its kinetic energy, the final energy is 80 percent of the initial energy. Equating the initial and final energies and solving for H, we can find the answer. The correct answer is 4.0 m.
Oops. Forgot my homework -- maybe I can get some sucker to do it for me.
Hmmm...