What is the net force acting on an object at t=2 with a given momentum equation?

In summary, the conversation discusses the equation for an object's momentum and how it can be used to determine the net force acting on the object at a specific time. The correct formula for this is F = dp/dt, and the calculation used to find the net force is not (21-1)/(2-0) but rather (21-1)/(2-0) = 10. The proper version of Newton's second law is F = d(mv)/dt.
  • #1
Nny
2
0

Homework Statement



An objects momentum is given by the following equation p(t) = 4t3-6t+1. What net force is acting on the objects at t=2?

Homework Equations



P=m*v
F=Δp/Δt

The Attempt at a Solution



So, I was thinking if F=m*a I can change a and get F=m*(Δv/Δt) and knowing what I know about p, I change it to F=Δp/Δt

So then I was just solving the equation for t=2 and t=0 to get (21-1)/(2-0) = 10

Is that correct or am I totally thinking about this wrong?
 
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  • #2
Remember that, F=dP/dt
 
  • #3
Hi Nny! :smile:
Nny said:
So, I was thinking if F=m*a I can change a and get F=m*(Δv/Δt) and knowing what I know about p, I change it to F=Δp/Δt

So then I was just solving the equation for t=2 and t=0 to get (21-1)/(2-0) = 10

as ben says, F = dp/dt, not ∆p/∆t,

so your basic idea is right, but your calculation is wrong

(btw, the proper version of good ol' Newton's second law is not F = ma, it's F = d(mv)dt … force = rate of change of momentum :wink:)
 

1. What is net force from momentum?

Net force from momentum is the overall force that is acting on an object, taking into account both the object's mass and velocity. It is a vector quantity, meaning it has both magnitude and direction.

2. How is net force from momentum calculated?

Net force from momentum is calculated using the formula F = ma, where F is the net force, m is the mass of the object, and a is the acceleration of the object. This formula is derived from Newton's second law of motion, which states that force is equal to mass times acceleration.

3. What is the relationship between net force and momentum?

The net force acting on an object is directly proportional to its change in momentum. This means that the greater the net force acting on an object, the greater its change in momentum will be. This relationship is described by Newton's second law of motion.

4. How does net force from momentum affect an object's motion?

Net force from momentum affects an object's motion by causing it to accelerate. If the net force acting on an object is in the same direction as its velocity, the object will speed up. If the net force is in the opposite direction, the object will slow down. If the net force is zero, the object will maintain a constant velocity.

5. Can net force from momentum be negative?

Yes, net force from momentum can be negative. This means that the force is acting in the opposite direction of the object's motion. For example, if an object is moving to the right and experiences a net force to the left, the net force would be negative. This would cause the object to slow down or change direction.

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