1 Motion – Newton’s Laws I’d rather be a hammer than a nail... - Simon and Garfunkel

2 Motion – Newton’s Laws 1. Every body continues in its state of rest or uniform motion unless it is acted upon by a net external force. 2. The acceleration of a body is equal to the net force acting on the body divided by the mass of the body. a = F NET / m F NET = ma 3. For every action, there is an equal and opposite reaction.

3 Motion – Newton’s Laws Who gets hit harder – the hammer or the nail?

4 Motion – Newton’s Laws Who would you rather be – the hammer or the nail?

5 Motion – Newton’s Laws Who would you rather be – the hammer or the nail? F on nail = F on hammer m nail a nail = m hammer a hammer a nail = ( m hammer / m nail ) a hammer

6 Motion – Newton’s Laws Who would you rather be – the hammer or the nail? F on nail = F on hammer m nail a nail = m hammer a hammer a nail = ( m hammer / m nail ) a hammer a nail >> a hammer

7 Motion – Newton’s Laws Who would you rather be – the hammer or the nail? F on nail = F on hammer m nail a nail = m hammer a hammer a nail = ( m hammer / m nail ) a hammer a nail >> a hammer I’d rather be a hammer than a nail!

8 Motion – Newton’s Laws If a cart pulls back on a horse with a force that is of equal magnitude to the force with which the horse pulls on the cart, how can a horse move a cart???? See Project Example – “Newton’s Third Law and the Ability of a Horse to Pull a Cart” can be found through links in the SCI190 Project Main Page SCI190 Project Main Page