• Linear momentum (p) is defined as the product of mass and velocity

Momentum is the product of mass and velocity

• Momentum is a vector quantity - it has both a magnitude and a direction
• This means it can have a negative or positive value
  • If an object travelling to the right has positive momentum, an object travelling to the left (in the opposite direction) has a negative momentum

   

• The SI unit for momentum is?kg m s?1

When the ball is travelling in the opposite direction, its velocity is negative.?Since momentum = mass × velocity, its momentum is also negative

• Both the tennis ball and the brick have the same momentum
• Even though the brick is much heavier than the ball, the ball is travelling much faster than the brick
• This means that on impact, they would both exert a similar force (depending on the time it takes for each to come to rest)