Download the App!

Get 24/7 study help with the Numerade app for iOS and Android! Enter your email for an invite.

You are driving home in your $750-\mathrm{kg}$ car at 15 $\mathrm{m} / \mathrm{s}$ . At a point45 $\mathrm{m}$ from the beginning of an intersection, you see a greentraffic light change to yellow, which you expect will last 4.0 $\mathrm{s}$and the distance to the far side of the intersection is 65 $\mathrm{m}$ (Fig. 64$)$ . (a) If you choose to accelerate, your car's engine willfurnish a forward force of 1200 $\mathrm{N}$ . Will you make it completelythrough the intersection before the light turns red? (b) If youdecide to panic stop, your brakes will provide a force of1800 $\mathrm{N} .$ Will you stop before entering the intersection?

Get the answer to your homework problem.

Try Numerade free for 7 days

Like

Report

a. Yesb. No

Physics 101 Mechanics

Chapter 4

Dynamics: Newton's Laws of Motion

Motion Along a Straight Line

Motion in 2d or 3d

Newton's Laws of Motion

Applying Newton's Laws

Moment, Impulse, and Collisions

Cornell University

Rutgers, The State University of New Jersey

Simon Fraser University

University of Winnipeg

Lectures

03:28

Newton's Laws of Motion are three physical laws that, laid the foundation for classical mechanics. They describe the relationship between a body and the forces acting upon it, and its motion in response to those forces. These three laws have been expressed in several ways, over nearly three centuries, and can be summarised as follows: In his 1687 "Philosophiæ Naturalis Principia Mathematica" ("Mathematical Principles of Natural Philosophy"), Isaac Newton set out three laws of motion. The first law defines the force F, the second law defines the mass m, and the third law defines the acceleration a. The first law states that if the net force acting upon a body is zero, its velocity will not change; the second law states that the acceleration of a body is proportional to the net force acting upon it, and the third law states that for every action there is an equal and opposite reaction.

04:30

In classical mechanics, impulse is the integral of a force, F, over the time interval, t, for which it acts. In the case of a constant force, the resulting change in momentum is equal to the force itself, and the impulse is the change in momentum divided by the time during which the force acts. Impulse applied to an object produces an equivalent force to that of the object's mass multiplied by its velocity. In an inertial reference frame, an object that has no net force on it will continue at a constant velocity forever. In classical mechanics, the change in an object's motion, due to a force applied, is called its acceleration. The SI unit of measure for impulse is the newton second.

02:07

You're approaching an…

0:00

A person driving her car a…

03:50

04:57

$A$ car with a mass of $13…

03:38

02:59

You are driving your car a…

02:53

(a) What force is required…

08:13

03:29

(III) A person driving her…

04:43

A car moving initially at …

05:42

A $1200-\mathrm{kg}$ car i…

11:55

A car that weighs $1.30 \t…

04:13

03:02

A car has a mass of 1500 k…

and our location AT T equals 4.0 seconds. So we can say that acceleration is gonna be equal to our maximum force going forward of the car divided by the mass of the car. So this legal to 1200 Newtons divided by the mass of the car being 750 kilograms. Therefore, this is equaling 1.6 meters per second squared. Now, Delta X is gonna be equal to the ex initial T plus 1/2 A T squared. And so this is an equal 15 meters per second times for seconds plus 1/2 times 1.6 meters per second squared times four seconds squared. And so delta X is one equal 72.8 meters. This is greater than 65 meters. Therefore, yes, he will make it through the intersection. So if you go your maximum acceleration, you can make it through the intersection before the light turns red. Now, part B is asking us, given that we haven't a maximum deceleration or, um, maximum negative acceleration. Can we stop before entering the intersection? So acceleration here would be the maximum force of breaking divided by mm. This is equally negative. 1800 Newtons, divided by 750 kilograms. Once again, this is equaling a negative. 2.4 meters per second squared and again we use we can use another. Tooni, Kiddo Matics Equation philosophy Final squared equals velocity Initial squared plus two times a Delta X on Do we know that velocity final squared would be zero? Uh, Therefore, Delta X is gonna be equal to negative velocities. Initial squared, divided by two a And this is giving us negative 15 meters per second squared, divided by two times negative 2.4. And, um, Delta X is gonna equal 46 0.875 meters And this is gonna be greater than 45 meters. Therefore no, you cannot stop before the intersection. No, um, you cannot stop. Ah, before entering intersection. That is the end of the solution. Thank you for watching

View More Answers From This Book

Find Another Textbook

01:34

In the experiment to test the presence of starch, Why is the leaf dipped in …

01:40

A stone is dropped down a deep well from rest. The well is 50 m deep. How lo…

03:44

Show that a light ray that strikes two mutually perpendicularreflecting …

01:05

5. Michael Phelps broke the Olympic record in100 m butterfly stroke with a c…

02:47

if line of sight and horizontal line are in same path then which angle is fo…

01:02

The resistance in the left gap of a metre Bridge is 10 ohm and the balance p…

A concave mirror of focal length 10cm produces 3times long final image. Find…

01:08

Object travels 16m in 4s and then another 16m in 2s. what is the average spe…

two similar magnetic poles strength in the ratio 1:2 are placed 1m? apart .f…

01:21

the resistance of a metallic wire becomes 8 times when a) length is doubled …