Question

1.Why does a child in a wagon seem to fall backward when you give the wagon a sharp pull forward?

2.State Newton's law that is application to why a driver or a passinger in a car needs to buckle up with a seat belt. Use this law to explain the importance of a seat belt.

Answer 1

1)This "falling" is the boy's Inertia; which is "the resistance of any physical object to a change in its state of motion or rest, or the tendency of an object to resist any change in its motion."

2) a longer stopping distance decreases the impact force. A large
amount of stretch in the seat belt will reduce the average impact force. The
best help a driver has is his or her seat belt. Another important thing about
the safety of a seat belt is that it helps restrain the person in the seat.
Seat belts can reduce the impact of a passenger to about a fifth of the impact
suffered by the body of the car. If the seat belt does what it is made to do
then it would slow you down extremely as soon as the crash occurs. The more the
seat belt holds you back the less momentum you have after making contact in a
crash. With no seat belt to stop the driver with the car, the driver would fly
free until stopped suddenly by the impact on the steering column, windshield,
etc.

The stopping distance is about a fifth of that with a seat belt,
causing the average impact force to be about five times as great. The work done to stop the driver
is equal to the average impact force on the driver multiplied by the distance
traveled in stopping during the crash. A crash which stops the car and driver
must take away all the kinetic energy, and the work-energy principle The

change in the kinetic energy of an object is equal to the net work done on the object.