Register to reply

Force*Time graph with respect to momentum

by Donnie_b
Tags: forcetime, graph, momentum, respect
Share this thread:
Sep17-07, 02:30 AM
P: 4

If the mass of the object is 3.0 kg, what is its final velocity over the 8.0 s time period?

This is the work I've done so far.

F∆t = m∆v
100 * 8.0 = 3.0 * v
v = 266.67

Now 267m/s seems quite high to me. So I think the problem Im having is that I'm reading the graph incorrectly and extrapolating the incorrect force from it. So basically, can anyone tell me if I have the correct amount of force listed down?
Phys.Org News Partner Science news on
Flapping baby birds give clues to origin of flight
Prions can trigger 'stuck' wine fermentations, researchers find
Socially-assistive robots help kids with autism learn by providing personalized prompts
Sep17-07, 03:46 AM
Sci Advisor
PF Gold
P: 4,980
One approach would be to re-scale the force axis by dividing by the mass of the object and effectively turning it into an acceleration-time graph. The change in speed is then given by the area under the graph.
Sep25-07, 05:04 PM
P: 1
The area under a Force-Time graph is Impulse (equivalent to change in momentum). You can find the area under the curve and that will equal your momentum change. This should allow you to calculate your velocity change.

Jul9-10, 02:51 PM
P: 2
Force*Time graph with respect to momentum

DonnieB, Fizznerd is right, you need the area under the curve, and you do not need calculus, as that is a trapezoid. THe area of a trapezoid is the average of the bases times the height, which is (4 + 8)seconds/2*100 N = 600 N*s. Set this to mv - mv0, and assuming v0 is zero get v final = 200 m/s.

Register to reply

Related Discussions
Force - Time graph Question Introductory Physics Homework 8
Need help with a force vs time graph. Introductory Physics Homework 3
Force vs time graph Introductory Physics Homework 10
Force vs Time Graph Introductory Physics Homework 3