The pendulum bobs in the figure are made of soft clay so that they stick together after impact. The mass of bob B is 14 times that of bob A. Bob B is initially at rest. If bob A is released from a height h above its lowest point, what is the maximum height attained by bobs A and B after the collision?

I also don't have any clue about this one! Please help, thanks.

Here's two or three clues.

For the velocity of A just before impact (Va), use conservation of energy.

g*h = (1/2)*Va^2

For the velocity of and b stuck together after impact (Vfinal) , use conservation of momentum. (It is not an elastic collision)
Ma*Va = Vfinal*(Ma + Mb)
= 15*Ma*Vfinal

Once you get Vfinal, use conservation of energy again to get the height that they rise together.

Thanks!

Thank you Drwls :)

To solve this problem, we can apply the principle of conservation of mechanical energy. The total mechanical energy of the system, which includes the gravitational potential energy and kinetic energy, should remain constant before and after the collision.

Let's break down the steps to solve the problem:

1. Calculate the potential energy of bob A when it is released from a height h. The potential energy is given by the formula: PE = mgh, where m is the mass of bob A and g is the acceleration due to gravity.

2. Determine the kinetic energy of bob A just before the collision. Since bob A is released from a height h, the potential energy is converted into kinetic energy. Therefore, the kinetic energy of bob A is given by the formula: KE = 1/2 * m * v^2, where v is the velocity of bob A just before the collision.

3. Apply the conservation of mechanical energy to determine the kinetic energy of bob B just before the collision. Since bob B is initially at rest, its kinetic energy is zero.

4. Use the principle of conservation of linear momentum to find the velocity of the composite system after the collision. The formula for linear momentum is: m1 * v1 = (m1 + m2) * vf, where m1 is the mass of bob A, m2 is the mass of bob B, v1 is the velocity of bob A just before the collision, and vf is the final velocity of the composite system after the collision.

5. Calculate the maximum height attained by the composite system (bobs A and B) after the collision. The maximum height can be determined by converting the kinetic energy of the composite system at the final velocity into potential energy: PE = mgh.

By following these steps, you can calculate the maximum height attained by bobs A and B after the collision.