Solving Force Problem: Finding Velocity and Force Requirements

  • Thread starter the_d
  • Start date
  • Tags
    Force
In summary, the problem is to find the force needed to give a system of bodies a velocity of 30 ft/s after moving 20 ft from rest. The work done by that force on the distance of 20 ft equals the change in kinetic energy. The coefficient of kinetic friction (0.20) must also be taken into account in the sum of forces acting on the object.
  • #1
the_d
127
0
My problem is to find the force needed to give the system of bodies a velocity of 30 ft/s after moving 20 ft. from rest.

Can anyone help me with this? All i have done is found EFx and EFy for the 50lb weight
 

Attachments

  • p1.JPG
    p1.JPG
    11.1 KB · Views: 339
Last edited:
Physics news on Phys.org
  • #2
Didn't you post this question earlier? (Or was it someone else with the same question?) As said, use the fact that the work done by that force on the distance of 20 ft equals the change of kinetic energy.
 
  • #3
is there an equation for that??
 
  • #4
the_d said:
is there an equation for that??

If you know the definition of work, and the definition of kinetic energy, you should be able to write down this equation yourself.
 
  • #5
so W = KE, where does the coeffeficient of kinetic friction play in all this??
 
  • #6
the_d said:
so W = KE, where does the coeffeficient of kinetic friction play in all this??

You didn't mention any kinetic friction coefficient.
 
  • #7
sorry, the kinetic friction is 0.20...
 
  • #8
does that play a role??
 
  • #9
the_d said:
does that play a role??

Yes, it does, because you have to include the force of friction into your sum of forces acting on the object.
 
  • #10
ok, i got ya
 

FAQ: Solving Force Problem: Finding Velocity and Force Requirements

What is a force and how is it measured?

A force is a push or pull that can cause an object to accelerate. It is measured in units of Newtons (N) and can be calculated by multiplying an object's mass (in kg) by its acceleration (in m/s^2).

How do I solve a force problem?

To solve a force problem, you will need to identify the forces acting on the object, determine the direction of each force, and calculate the net force by adding or subtracting the forces. Then, use Newton's second law (F=ma) to find the acceleration of the object.

What is Newton's first law of motion?

Newton's first law of motion, also known as the law of inertia, states that an object will remain at rest or in motion with a constant velocity unless acted upon by an unbalanced force. In other words, objects will maintain their state of motion unless a force causes them to change it.

Can forces cancel each other out?

Yes, forces can cancel each other out if they are equal in magnitude and opposite in direction. This is known as a balanced force, and it will result in no change in an object's motion.

What is friction and how does it affect forces?

Friction is a force that resists the motion of two surfaces in contact with each other. It can either increase or decrease the net force acting on an object, depending on the direction of the force. For example, friction can slow down an object moving in one direction, but it can also help an object move in another direction (such as when a car's tires grip the road to move forward).

Back
Top