How much force and energy for moving a frictionless object

[5P@N]

Homework Statement

I have an object of 10 kg
It is to be displaced 2 meters
Assume a frictionless surface, and no wind resistance
The object begins as stationary, then is moved that distance in the span of .5 seconds.

Homework Equations

Force = mass* acceleration
acceleration = (delta velocity) / time
velocity = (delta position) / time

The Attempt at a Solution

initial velocity is 0
final velocity is: (2 - 0) meters / .5 second = 2 meters / .5 seconds= 4 meters per second
acceleration = (4 m/s - 0 m/s) / .5 seconds = 8 meters / second^2
8(m/s^2) * 10 kg = 80 Newtons

Correct?

 

[haruspex]

Homework Statement

I have an object of 10 kg
It is to be displaced 2 meters
Assume a frictionless surface, and no wind resistance
The object begins as stationary, then is moved that distance in the span of .5 seconds.

Homework Equations

Force = mass* acceleration
acceleration = (delta velocity) / time
velocity = (delta position) / time

The Attempt at a Solution

initial velocity is 0
final velocity is: (2 - 0) meters / .5 second = 2 meters / .5 seconds= 4 meters per second
acceleration = (4 m/s - 0 m/s) / .5 seconds = 8 meters / second^2
8(m/s^2) * 10 kg = 80 Newtons

Correct?

You have mot stated what you are asked to find. You seem to have assumed a constant force. Is that given?

 

[berkeman]

Homework Statement

I have an object of 10 kg
It is to be displaced 2 meters
Assume a frictionless surface, and no wind resistance
The object begins as stationary, then is moved that distance in the span of .5 seconds.

Homework Equations

Force = mass* acceleration
acceleration = (delta velocity) / time
velocity = (delta position) / time

The Attempt at a Solution

initial velocity is 0
final velocity is: (2 - 0) meters / .5 second = 2 meters / .5 seconds= 4 meters per second
acceleration = (4 m/s - 0 m/s) / .5 seconds = 8 meters / second^2
8(m/s^2) * 10 kg = 80 Newtons

Correct?

Are you told to assume a constant force?

 

[haruspex]

You have not provided the whole question. What exactly are you supposed to find? Minimum energy? Least maximum magnitude force?
As berkeman posted, you seem to have assumed a constant force, but even then your calculation is wrong:

final velocity is: (2 - 0) meters / .5 second = 2 meters / .5 seconds= 4 meters per second

That calculates the average speed, not the final speed. Check your answer: constant acceleration of 8m/s² for 0.5 seconds from rest would travel how far?

 

[5P@N]

What do you all mean when you say: "constant force"?

What would this constant force do? What are its attributes?

.5^2 = .25
.25 *8 = 2
since the object moved 2 meters, this appears correct. Or what am I missing?

 

[haruspex]

What do you all mean when you say: "constant force"?

What would this constant force do? What are its attributes?

.5^2 = .25
.25 *8 = 2
since the object moved 2 meters, this appears correct. Or what am I missing?

Review the equation relating time, distance, initial speed, and constant acceleration. You are missing something.

Please state the entire question, exactly as presented to you.