Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 4: Q2. (page 98)

A box rests on the (frictionless) bed of a truck. The truck driver starts the truck and accelerates forward. The box immediately starts to slide towards the rear of the truck bed. Discuss the motion of the box, in terms of Newton’s laws, as seen (a) by Mary standing on the ground besides the truck, and (b) by Chris who is riding on the truck (See below figure).

Short Answer

Expert verified

According to Newton’s law, the boy’s upper body will stay at rest but its feet will start moving as they are in contact with the ground.

Step by step solution

01

Step 1. Use Newton’s first law

According to Newton’s first law, an object in a state of rest will continue to be so, and an object in a state of motion will continue to be so unless acted upon by an external object.

02

Step 2. Motion seen by Mary

As seen by Mary, who is on the ground, initially, both truck and box are at rest. As soon as the truck starts, an acceleration a acts on it, and as there is no force on the box to move it forward (it is not tied to the truck).

Hence, it will continue to stay at rest according to the first law of motion.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Suppose an object is accelerated by a force of 100 N. Suddenly, a second force of 100 N in the opposite direction is exerted on the object so that the forces cancel. The object

(a) is brought to rest rapidly.

(b) decelerates gradually to rest.

(c) continues at the velocity it had before the second force was applied.

(d) is brought to rest, and then it accelerates in the direction of the second force.

A flatbed truck is carrying a heavy crate. The coefficient of static friction between the crate and the bed of the truck is 0.75. What is the maximum rate at which the driver can decelerate and still avoid having the crate slide against the bed of the truck?

Two crates, of mass 65 kg and 125 kg, are in contact and at rest on a horizontal surface (Fig. 4–57). A 650-N force is exerted on the 65-kg crate. If the coefficient of kinetic friction is 0.18, calculate (a) the acceleration of the system, and (b) the force that each crate exerts on the other (c) Repeat with the crates reversed.

FIGURE 4-57Problem 49.

One 3.2-kg paint bucket is hanging by a massless cord from another 3.2-kg paint bucket, also hanging by a massless cord, as shown in Fig. 4–49. (a) If the buckets are at rest, what is the tension in each cord? (b) If the two buckets are pulled upward with an acceleration of by the upper cord, calculate the tension in each cord.

(a) What is the acceleration of two falling sky divers (total mass = 132 kg including parachute) when the upward force of air resistance is equal to one-fourth of their weight? (b) After opening the parachute, the divers descend leisurely to the ground at constant speed. What now is the force of air resistance on the sky divers and their parachute?

See Fig. 4–44.
See all solutions

Recommended explanations on Physics Textbooks

Solid State Physics

Read Explanation

Kinematics Physics

Read Explanation

Famous Physicists

Read Explanation

Translational Dynamics

Read Explanation

Electricity and Magnetism

Read Explanation

Quantum Physics

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free