# Newton's first Law

1. Mar 14, 2016

### alexandria

1. The problem statement, all variables and given/known data

2. Relevant equations
no formula's required

3. The attempt at a solution
please explain if these answers are correct, thanks
34.

Large transport trucks have a hard steel barrier between the load and the driver’s cab In order to protect the driver and prevent injury. According to Newton’s first law, an object will remain at rest or at a constant speed in a straight line, unless it is affected by an external unbalanced force. Keeping this in mind, if the truck did not have a hard steel barrier between the load and the driver’s cab, and were to abruptly stop, the load would continue to move at its original speed and would collide with the truck. The force that causes the truck to stop would not act on the load, and so the load would continue moving. By installing a hard steel barrier between the load and the driver’s cab, it would prevent the load from coming forward and crushing the truck or the driver inside of it.

35.

As the cart rides up to the top of the second hill, the passengers will feel as though they are airborne for a short period of time. This can be explained using Newton’s first law. According to Newton’s first law, an object will remain at rest or at a constant speed in a straight line, unless it is affected by an external unbalanced force. In this case, as the roller coaster travels down a hill, the passenger’s inertia will keep them moving in their original ‘upward’ motion, causing them to lift off their seats and experience a slightly airborne sensation. Luckily, seatbelts are installed to pull the passengers down towards their seats, also making them more part of the roller coaster and its motion.

36.

Re-calling Newton’s first law, that an object will maintain its motion, unless it is affected by an external unbalanced force, we can understand what is happening to the passengers in a roller coaster when it quickly turns corners. In this case, as the cart turns corners (left or right), the passenger’s inertia would keep them moving in their original straight motion, causing them to collide with the sides of the cart and giving them a feeling that they are being pushed out of the cart. For example: if the roller coaster was originally moving in a straight motion, then made a right turn, the passengers would continue moving at their original speed and direction, and that would cause them to slide to the left of the cart. The force acting upon the roller coaster, is not acting on the passengers in it, and so they would continue at their original motion, causing them to feel as though they are being pushed out of the roller coaster.

37.

* In the case of key Question 35, passengers are required to wear seatbelts, so that they are pulled towards their seats.

*what safety measures would be used to counteract the effects of newtons first law on the ride in key qts 36?

2. Mar 14, 2016

### Staff: Mentor

34 looks right. Perhaps the phrase "unsecured load" could be incorporated in your answer, with its ramifications precisely explained.

Considering 35. When I travel home I drive over a hill, yet I never have a sensation of being airborne. Can you explain why?

3. Mar 14, 2016

### alexandria

does it depend on how steep the hill is?
for qts 36 and 37, can you explain them to me as well.
and also for qts 34, what do you mean by 'unsecured load' and how would i incorporate that into my answer?
thanks

4. Mar 15, 2016

### haruspex

That's not quite it. Can you identify more precisely the point(s) in the course where they will sit less heavily in their seats?
Yes, stroke of luck that!

5. Mar 15, 2016

### Staff: Mentor

That is only half of the answer. What else is involved?
Your 36 looks good.