1. The problem statement, all variables and given/known data I need a method for my experimental lab procedure that allows me to use the same force multiple times. I need to provide a constant force to object A that causes it to collide with object B -- on a horizontal plane. I thought of using a spring on object A where F=kx but assuming I have the maximum compression how would I determine the spring constant. Another method I thought was to place object A on an inclined plane where it would roll down. For this method I thought of using the constant acceleration equations and then using the equation F=ma to find the applied force (I have displacement, initial velocity - 0, and I can time the length at which it rolls down the inclined plane thus solving for acceleration) However, the problem with this method is that I have to factor in the friction. Can anyone help me work out my problems or provide me with new methods? 2. Relevant equations The five constant acceleration equations (?) F=ma 3. The attempt at a solution See above.