i know this might seem kind of long. but if you could please help me, i'd greatly appreciate it.
a. suppose you have a tug of war with a friend who is the same size and weight as you are. You both pull as hard as you can, but neither of you seems to be winning. You move a little one way or the other, but mostly you are just at rest (although sweating some). Compare the magnitude of the force exerted by you on your friend, with the magnitude of the force exerted by your friend on you. Are they the same or different? If they are not the same, which is larger? Why or why not?
b. Now you have a tug of war with your kid sister (who is much smaller and lighter than you). Again you both pull hard but end in a standoff with neither of you moving much. Compare the magnitude of the force exerted by you on your sister, with the magnitude of the force she exerts on you. Are they the same or different? If they are not the same, which is larger? Why or why not?
c. The next tug of war is still with your kid sister but she is now standing on her skateboard. You can now make her roll across the floor (with constant speed) when you pull hard. In this situation compare the magnitude of the force exerted by you on your sister, with the magnitude of the force she exerts on you. Are they the same or different? If they are not the same, which is larger? Why or why not?
d. Now you pull your sister across the floor so that she moves with increasing speed (accelerates). Compare the magnitude of the force exerted by you on your sister, with the magnitude of the force she exerts on you. Are they the same or different? If they are not the same, which is larger? Why or why not?
e. Due to the drivers not paying attention, a small car and a big truck collide, both are initially moving at 5mph towards each other. Compare the magnitude of the force the truck exerts on the car to the magnitude of the force the car exerts on the truck. Which vehicle would you rather ride in? Describe why you made your choice.
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Verified answer
a-e Same. In every scenario above, the forces are the same.
Newton's third law states that if you exert a force on an object (your sister, your friend, your mother, a wall, ANYTHING) it exerts an equal and opposite force back on you.
But the person being pulled might wonder how they are being moved if they are exerting as much force on their opponent as their opponent is exerting on them. To answer the question who will be accelerated, you have to use Newton's SECOND Law, which states that the sum of the forces acting on an object equal its mass times the resulting acceleration.
Consider the last question, if the big truck exerts the same force on the small car as the small car exerts on the big truck, then why should it matter which vehicle you ride in? Well, if you consider the big truck and the force exerted on it you get
F = Ma solve for a and you get a = F/M
If you consider the car using Newton's second law you get
F = ma solve for a and you get a = F/m
I don't know about you, but I would rather be in the vehicle with the smaller acceleration, easier on the spine, and all... And the Truck's acceleration has the LARGER mass in the denominator, so it will have the smaller acceleration than the poor car with the little m in its denominator.