Question

louisa builds the body of a race car out of cardboard. she tapes a straw to the cardboard so that one end of the straw is tilted up and the other end hangs over the back of the car. then, she places an inflated balloon over the tilted end of the straw and releases the mouth of the balloon to allow air to flow through the straw. the race car rolls forward as the balloon releases air through the straw, as shown in the picture below.
how does louisa’s race car demonstrate newton’s third law of motion?
a. the forward movement of the car forces air to leave the balloon faster
b. the balloon pushes against the air, which results in a zero net force on the balloon
c. the balloon pushes the air out, and the air pushes back on the balloon
d. the forward movement of the car forces air to leave the balloon slower

Explanation:

Newton's third law states that for every action, there is an equal and opposite reaction. In this car, the balloon pushing air backward (action) creates an equal and opposite force of air pushing the balloon (and attached car) forward (reaction), which matches option C. The other options incorrectly describe the force relationship or net force.

Answer:

C. The balloon pushes the air out, and the air pushes back on the balloon