How Does Force Affect Object Speed and Position?

In summary, the conversation discusses the calculation of the speed of a 1.7kg object at different locations, given its initial speed and position. The relevant equations of W=Fd, K=1/2mv^2, and Vf^2=Vi^2+2ad are mentioned, but the speaker is unsure of how to begin. Another person suggests computing the initial kinetic energy and how it changes as the object moves, and explains that the kinetic energy contains the necessary information to calculate the speed and location. The question of where the object's speed would be slower than at its initial position of x=0.27m is also raised.
  • #1
matt@USA
25
0

Homework Statement



The force shown in the figure acts on a 1.7kg- object whose initial speed is 0.44m/s and initial position is x=.27m. Find the speed of the object when it is at the location x=.99m. At what location would the object's speed be 0.32m/s ?



Homework Equations


I know that W=Fd. K=1/2mv^2. Vf^2=Vi^2+2ad.



The Attempt at a Solution


I have no clue where to start. I am completely lost. Where do, or how do I begin? Thanks for the help!
 

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  • #2
compute the initial KE, at its initial location.
That KE is changed by the F.d , as it moves along:
(.8N)(.23m) extra as it crosses the 0.5m mark. etc.
 
  • #3
Ok, so how does finding the Joules help me solve for velocity and location?
 
  • #4
the KE contains all the info to find out how fast it's going. (½mv.v)
it's about KE _at_ a location , just like it used to be "velocity at a time"

Notice that they ask "where was it going slower than at 0.27m?"
 
  • #5


I would suggest starting by identifying the known values and the unknown values in this problem. The known values are the mass of the object (1.7kg), its initial speed (0.44m/s), and its initial position (x=0.27m). The unknown values are the object's final speed at x=0.99m and the location where its speed is 0.32m/s.

Next, we can use the equations you listed to find the final speed and location. We can use the equation Vf^2=Vi^2+2ad to find the final speed at x=0.99m, since we know the initial speed, acceleration, and displacement. Then, we can use the equation K=1/2mv^2 to find the location where the object's speed is 0.32m/s, since we know the mass and the speed.

It may also be helpful to draw a diagram and label the known and unknown values on it. This can help visualize the problem and guide your calculations.

Overall, the key is to identify the known and unknown values, and then use the appropriate equations to solve for the unknown values. Remember to pay attention to units and use the correct formulas for each situation. Good luck!
 

Related to How Does Force Affect Object Speed and Position?

1. What is the relationship between force and position?

The relationship between force and position is described by Newton's second law of motion, which states that the force applied to an object is directly proportional to the object's mass and acceleration. This means that the greater the force applied to an object, the greater its acceleration will be, and the greater its displacement will be.

2. How is force and position measured?

Force is typically measured in units of Newtons (N) using a spring scale or force meter. Position, or displacement, is measured in units of meters (m) using a ruler, tape measure, or other measuring device.

3. How does the direction of force affect an object's position?

The direction of the force applied to an object determines the direction of its acceleration. If the force is applied in the same direction as the object's motion, it will speed up. If the force is applied in the opposite direction, it will slow down. If the force is applied perpendicularly to the object's motion, it will change its direction of motion.

4. What is the difference between net force and individual forces?

Net force is the sum of all the individual forces acting on an object. Individual forces may act in different directions and cancel each other out, resulting in a net force of zero and no change in the object's position. However, if the net force is not zero, the object will accelerate in the direction of the net force.

5. How does friction affect an object's position?

Friction is a force that resists the motion of an object and acts in the opposite direction. This means that if an object is moving, friction will act in the opposite direction as its motion, causing it to slow down. If an object is at rest, friction will act in the direction opposite to the force applied to it, preventing it from moving. Therefore, friction can affect an object's position by either slowing it down or preventing it from moving.

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