/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 67 A projectile is fired horizontal... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 2: Problem 67

A projectile is fired horizontally with an initial speed of \(20 \mathrm{~m} / \mathrm{s}\). Its horizontal speed \(3 \mathrm{~s}\) later will be (A) \(20 \mathrm{~m} / \mathrm{s}\) (B) \(6.67 \mathrm{~m} / \mathrm{s}\) (C) \(60 \mathrm{~m} / \mathrm{s}\) (D) \(29.4 \mathrm{~m} / \mathrm{s}\)

Short Answer

Expert verified
The horizontal velocity of the projectile remains constant because it is unaffected by gravity. Therefore, the horizontal speed 3 seconds later will be the same as its initial speed, which is \(20 \mathrm{~m} / \mathrm{s}\). The correct answer is (A) \(20 \mathrm{~m} / \mathrm{s}\).

Step by step solution

01

1. Identifying what affects horizontal velocity

In a projectile motion problem, the only force that acts on the projectile is the downward gravitational force. This force does not affect the horizontal velocity directly, so the horizontal velocity remains constant throughout the motion.
02

2. Finding the horizontal velocity of the projectile after 3 seconds

Since the horizontal velocity remains constant and unaffected by the downward gravitational force, the horizontal velocity after 3 seconds will be the same as its initial horizontal velocity. Thus, the horizontal velocity will be 20 m/s.
03

3. Choose the correct answer

Now that we have found the horizontal velocity after 3 seconds (20 m/s), we can easily identify the correct option among the given alternatives. The correct answer is (A) 20 m/s.

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.

Over 30 million students worldwide already upgrade their learning with 91影视!

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

A boy can throw a stone up to a maximum height of \(10 \mathrm{~m}\). The maximum horizontal distance that the boy can throw the same stone up to will be (A) \(20 \sqrt{2} \mathrm{~m}\) (B) \(10 \mathrm{~m}\) (C) \(10 \sqrt{2} \mathrm{~m}\) (D) \(20 \mathrm{~m}\)

A particle is projected with a speed of \(40 \mathrm{~m} / \mathrm{s}\) at an angle of \(60^{\circ}\) with the horizontal. At what height speed of particle becomes half of initial speed \(\left(g=10 \mathrm{~m} / \mathrm{s}^{2}\right)\). (A) \(30 \mathrm{~m}\) (B) \(45 \mathrm{~m}\) (C) \(37.5 \mathrm{~m}\) (D) \(60 \mathrm{~m}\)

A ball is released from the top of a tower of height \(h\) meters. It takes \(T \mathrm{~s}\) to reach the ground. What is the position of the ball at \(\frac{T}{3}\) second? (A) \(\frac{8 h}{9}\) metres from the ground (B) \(\frac{7 h}{9}\) metres from the ground (C) \(\frac{h}{9}\) metres from the ground (D) \(\frac{17 h}{18}\) metres from the ground

Take the \(z\)-axis as vertical and \(x y\) plane as horizontal. A particle \(A\) is projected speed at \(4 \sqrt{2} \mathrm{~m} / \mathrm{s}\) at an angle \(45^{\circ}\) to the horizontal in the \(x z\). Particle \(B\) is also projected at same instant but with speed \(5 \mathrm{~m} / \mathrm{s}\) at an angle \(\tan ^{-1}(4 / 3)\) with horizontal in \(y z\) plane, then which of the following statement/s is/are correct? ( \(g=10 \mathrm{~m} / \mathrm{s}^{2}\) ) (A) Magnitude of relative velocity of \(A\) with respect to \(B\) is \(5 \mathrm{~m} / \mathrm{s}\) during motion. (B) Particle \(A\) and \(B\) again hit the ground at the same instant. (C) The separation between \(A\) and \(B\) when they hit the ground is \(4 \mathrm{~m}\). (D) The path of \(A\) with respect to \(B\) is straight line.

A \(2 \mathrm{~m}\) wide truck is moving with a uniform speed \(v_{0}=\) \(8 \mathrm{~m} / \mathrm{s}\) along a straight horizontal road. A pedestrian starts to cross the road with a uniform speed \(v\) when the truck is \(4 \mathrm{~m}\) away from him. The minimum value of \(v\) so that he can cross the road safely is (A) \(2.62 \mathrm{~m} / \mathrm{s}\) (B) \(4.6 \mathrm{~m} / \mathrm{s}\) (C) \(3.57 \mathrm{~m} / \mathrm{s}\) (D) \(1.414 \mathrm{~m} / \mathrm{s}\)
See all solutions

Recommended explanations on Physics Textbooks

Linear Momentum

Read Explanation

Electromagnetism

Read Explanation

Magnetism and Electromagnetic Induction

Read Explanation

Further Mechanics and Thermal Physics

Read Explanation

Wave Optics

Read Explanation

Work Energy and Power

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.