Skip to main content
Ch 11: Impulse and Momentum
Knight Calc - Physics for Scientists and Engineers 5th Edition
Knight Calc5th EditionPhysics for Scientists and EngineersISBN: 9780137344796Not the one you use?Change textbook
Chapter 11, Problem 5

In FIGURE EX11.5, what value of Fmax gives an impulse of 6.0 N s?

Verified step by step guidance
1
Step 1: Recall the formula for impulse, which is given by \( J = F \cdot \Delta t \), where \( J \) is the impulse, \( F \) is the force, and \( \Delta t \) is the time interval during which the force acts.
Step 2: From the graph, observe that the force \( F_{\text{max}} \) acts over a time interval \( \Delta t \) from \( t = 4 \, \text{s} \) to \( t = 10 \, \text{s} \). Calculate \( \Delta t \) as \( \Delta t = 10 - 4 = 6 \, \text{s} \).
Step 3: Substitute the given impulse \( J = 6.0 \, \text{N} \cdot \text{s} \) and the time interval \( \Delta t = 6 \, \text{s} \) into the formula \( J = F \cdot \Delta t \). Rearrange the formula to solve for \( F \): \( F = \frac{J}{\Delta t} \).
Step 4: Perform the substitution: \( F = \frac{6.0}{6} \). This will give the value of \( F_{\text{max}} \).
Step 5: Interpret the result: The calculated \( F_{\text{max}} \) represents the maximum constant force that acts over the time interval \( \Delta t \) to produce the given impulse.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
5m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Impulse

Impulse is defined as the change in momentum of an object when a force is applied over a period of time. It is mathematically represented as the product of force and the time duration for which the force acts. In this context, the impulse is given as 6.0 N·s, indicating the total effect of the force applied over the specified time interval.
Recommended video:
Guided course
06:00
Impulse & Impulse-Momentum Theorem

Force-Time Graph

A force-time graph visually represents how force varies with time. The area under the curve of this graph corresponds to the impulse experienced by an object. In the provided graph, the force is constant at Fmax for a certain duration, allowing for straightforward calculation of impulse by multiplying Fmax by the time interval during which the force is applied.
Recommended video:
Guided course
05:59
Velocity-Time Graphs & Acceleration

Calculating Fmax

To find the maximum force (Fmax) that results in a specific impulse, one can use the relationship between impulse, force, and time. Given the impulse (6.0 N·s) and the duration of the force application (which can be inferred from the graph), Fmax can be calculated using the formula: Impulse = Fmax × time. This allows for determining the required force to achieve the desired impulse.
Recommended video:
Guided course
04:15
Calculating Dot Product Using Vector Components