A 0.060 kg tennis ball, moving with a speed of 7.00 m/s has a head-on collision with a 0.086 kg ball initially moving in the same direction at a speed of 3.10 m/s. Assume a perfectly elastic collision and take the initial direction of the balls as positive.

you have two equations:

first, conservation of momentum. Solve for one ball's final velocity in terms of the other.
then write conservation of eneryg. Substiture your first velocity, then expand it,and solve. A bit of algebra is required.

To solve this problem, we need to use the principles of conservation of momentum and kinetic energy.

1. Conservation of momentum: In a collision, the total momentum before the collision is equal to the total momentum after the collision. Mathematically, we can write it as:

(m1 * v1_initial + m2 * v2_initial) = (m1 * v1_final + m2 * v2_final)

where m1 and m2 are the masses of the objects and v1_initial, v2_initial are their initial velocities. v1_final and v2_final are their final velocities after the collision.

2. Conservation of kinetic energy: In a perfectly elastic collision, the total kinetic energy before the collision is equal to the total kinetic energy after the collision. Mathematically, we can write it as:

(1/2 * m1 * v1_initial^2 + 1/2 * m2 * v2_initial^2) = (1/2 * m1 * v1_final^2 + 1/2 * m2 * v2_final^2)

Using these two equations, we can solve for the final velocities of the objects after the collision.

Let's plug in the values given in the problem:

m1 = 0.060 kg (mass of the tennis ball)
v1_initial = 7.00 m/s (initial velocity of the tennis ball)
m2 = 0.086 kg (mass of the other ball)
v2_initial = 3.10 m/s (initial velocity of the other ball)

We need to solve for v1_final and v2_final.

Applying the conservation of momentum equation:

(0.060 kg * 7.00 m/s) + (0.086 kg * 3.10 m/s) = (0.060 kg * v1_final) + (0.086 kg * v2_final)

(0.42 kg·m/s) + (0.2666 kg·m/s) = (0.060 kg * v1_final) + (0.086 kg * v2_final)

0.6866 kg·m/s = (0.060 kg * v1_final) + (0.086 kg * v2_final) -- (Equation 1)

Now, applying the conservation of kinetic energy equation:

(1/2 * 0.060 kg * 7.00 m/s^2) + (1/2 * 0.086 kg * 3.10 m/s^2) = (1/2 * 0.060 kg * v1_final^2) + (1/2 * 0.086 kg * v2_final^2)

(0.021 kg·m^2/s^2) + (0.012964 kg·m^2/s^2) = (0.030 kg * v1_final^2) + (0.043 kg * v2_final^2)

0.033964 kg·m^2/s^2 = (0.030 kg * v1_final^2) + (0.043 kg * v2_final^2) -- (Equation 2)

We now have a system of equations (Equation 1 and Equation 2) that we can solve using algebraic methods or numerical methods (such as substitution, elimination, or solving equations numerically).

Solving this system will give us the final velocities of both balls after the collision.