Verifying Newton's Laws: Finding Acceleration & Contact Forces

In summary, Newton's laws of motion state that an object will continue moving in a straight line unless acted on by an external force.
  • #1
konichiwa2x
81
0
Hi I have a problem and a doubt regarding Newton's laws of motion.
Consider three blocks of 5,2,5kg respectively placed one over the other and dropped from the top of a tower. (the 5 kg if at the top, 2kg in the middle and the 5kg at the bottom).

i) Find the acceleration of each block.

My calculations give me 'g'. Wont the acceleration be same for all three blocks?

ii) Find the contact forces between each block.

I got 0 as the answer for all the contact forces. I am not sure whether it is right though.


2) The second part of the question is: Consider the same details. Now, A 10N force is applied (directed upwards) on the 5kg block(which is at the bottom) from downwards.

i) Find 'a' between the blocks.
Here is my work:
5g - f2 = 5a
2g + f2 - f1 = 2a
5g + f1 - 10 = 5a

solving i got a = 55/6

ii) find the contact forces between the block.
f2 = 25/6 ; f1=575/6


Can someone please verify what I have done?Thanks!
 
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  • #2
one more doubt. if I use pseudo forces to calculate the acceleration of something, am I calculating its acceleration with respect to the non-intertial frame or the acceleration with respect to the ground frame(stationary frame)? :confused:

Please help
 
  • #3
Hi I have a problem and a doubt regarding Newton's laws of motion.
Consider three blocks of 5,2,5kg respectively placed one over the other and dropped from the top of a tower. (the 5 kg if at the top, 2kg in the middle and the 5kg at the bottom).

i) Find the acceleration of each block.

My calculations give me 'g'. Wont the acceleration be same for all three blocks?

ii) Find the contact forces between each block.

I got 0 as the answer for all the contact forces. I am not sure whether it is right though.
You are correct. All three blocks accelerate with gravity (g), and since all are accelerating at the same rate, there is no net force between them. If however, there was air resistance on the lead block then the other two would be pushing against the lead block, and the last block would push against the middle block.

I'll get back to you later on the other problem. :smile:
 
  • #4
ok thanks.
 

1. What are Newton's Laws of Motion?

Newton's Laws of Motion are three physical laws that describe the behavior of objects in motion. The first law states that an object at rest will remain at rest and an object in motion will remain in motion at a constant velocity unless acted upon by an external force. The second law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. The third law states that for every action, there is an equal and opposite reaction.

2. How can we verify Newton's Laws of Motion experimentally?

To verify Newton's Laws of Motion experimentally, we can conduct various experiments that involve measuring the acceleration and contact forces of objects in different scenarios. These experiments can include using inclined planes, pulley systems, and free-body diagrams to analyze the forces acting on an object and its resulting motion.

3. What is the importance of verifying Newton's Laws of Motion?

Verifying Newton's Laws of Motion is important because they are fundamental principles of physics that explain the behavior of objects in motion. These laws are the basis for understanding and predicting the motion of objects in everyday life and in more complex systems such as space travel and engineering projects.

4. How do acceleration and contact forces relate to Newton's Laws of Motion?

Acceleration and contact forces are directly related to Newton's Laws of Motion. The second law states that the acceleration of an object is directly proportional to the net force acting on it. This means that the greater the force applied to an object, the greater its acceleration will be. Contact forces, such as friction and normal force, are also important in understanding the motion of objects as they can affect the acceleration of an object.

5. What are some real-world examples of Newton's Laws of Motion in action?

There are many real-world examples of Newton's Laws of Motion in action. For example, the first law can be seen in the behavior of a ball rolling on a flat surface, as it will continue rolling until it encounters friction or another external force. The second law can be observed when pushing a shopping cart, as the greater the force applied, the greater the acceleration will be. The third law can be seen in action when a rocket launches, as the force of the exhaust pushing downwards results in an equal and opposite force propelling the rocket upwards.

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