Understanding Moments and Momentum

Maya and Grace are trying to balance a seesaw. What is the condition for equilibrium in terms of moments?

• The sum of clockwise moments equals the sum of anticlockwise moments.

• The sum of all forces equals zero.

• The sum of all moments equals zero.

• The sum of all forces and moments equals zero.

Abigail and Arjun are discussing physics, and Abigail asks Arjun, "What is the formula for calculating the momentum of an object?"

Henry and Luna are playing a game of marbles. When they collide their marbles, which of the following statements is true about the conservation of momentum?

• Momentum is conserved only in elastic collisions.

• Momentum is conserved in both elastic and inelastic collisions.

• Momentum is not conserved in any type of collision.

• Momentum is conserved only in inelastic collisions.