Understanding the Relationship Between Force, Momentum, and Impulse

In summary, force and momentum are related through the concept of time. Force is applied over time to change an object's momentum, and the equations F=ma and P=mv demonstrate this relationship. With calculus, this relationship can be expressed more precisely. Impulse is also related to momentum, as it is a force acting over a certain amount of time, and can explain why objects may or may not break when dropped on different surfaces.
  • #1
zeshkani
29
0
Is force related to Momentum or momentum to force in anyway
F=ma and P=mv
 
Physics news on Phys.org
  • #2
Yes, the link between the two is time. Essentially, force is applied over time to change an objects momentum.

Because F = m a, and a =[tex]\Delta[/tex]v / t
then F = m v/t
As you said P = mv so we get
F = P/t or P = Ft
 
  • #3
With calculus, the equations become more instantaneous and exact:

F=ma=m(dv/dt)=dp/dt-v(dm/dt).

If dm=0 (for instance, not a rocket) then:

F=dp/dt
 
  • #4
thx a lot :)
 
  • #5
Also, do you know the concept of Impulse? It has the same dimensions of momentum, but is more precisely defined as a Force acting over a certain amount of time. That's why when you drop an egg on a pillow, it will not break, but when you drop an egg on concrete, it will. Because the egg has some mass m and velocity v, and therefore some momentum p = mv, this momentum is numerically equal to the reactive force of the ground(or pillow) multiplied by the time interval it spends on that respective surface.

The pillow cushions the fall and therefore increases the time interval, in effect decreasing the force and keeping the egg from breaking. When you drop it on the concrete, the time interval is very short, and so the force on the egg is large (which is why it breaks).
 

1. What is the relationship between force and momentum?

The relationship between force and momentum is described by Newton's Second Law of Motion, which states that the force acting on an object is equal to the rate of change of its momentum. In simpler terms, the greater the force applied to an object, the greater its change in momentum will be.

2. How does force affect an object's momentum?

Force is directly related to an object's momentum, meaning that any changes in force will result in a corresponding change in momentum. This is because force is what causes an object to accelerate, which in turn affects its momentum.

3. Can momentum exist without force?

No, momentum cannot exist without force. In order for an object to have momentum, it must be in motion, and motion requires a force to act upon it. Even if an object is moving at a constant speed, it still has momentum, which means that a force must have been applied to it at some point to set it in motion.

4. How does mass factor into the relationship between force and momentum?

Mass is an important factor in the relationship between force and momentum. According to Newton's Second Law, the greater the mass of an object, the more force is needed to accelerate it and change its momentum. This means that objects with larger masses will have a greater momentum for a given force.

5. Can an object have momentum without being in motion?

No, an object cannot have momentum without being in motion. As mentioned earlier, momentum is a measure of an object's motion, so if an object is not moving, it does not have any momentum. However, an object can have a non-zero momentum when it is at rest if it has a non-zero mass, but this momentum is referred to as "rest mass" and is not related to motion.

Similar threads

Replies
3
Views
1K
Replies
7
Views
1K
Replies
12
Views
829
  • Mechanics
Replies
9
Views
1K
Replies
52
Views
2K
Replies
9
Views
864
Replies
30
Views
1K
Replies
1
Views
6K
Replies
3
Views
951
Back
Top