A 120 k g dolphin decelerates from 15 m / s to 7.5 m / s in 5 s to join another dolphin in play. What average force was exerted to slow the first dolphin if it was moving horizontally? (Assume that gravitational force is balanced by the buoyant force of the water)

Option 1 - <p><span class="mathml" contenteditable="false"> <math> <mn>120</mn> <mi> </mi> <mi>N</mi> </math> </span></p>
Option 2 - <p><span class="mathml" contenteditable="false"> <math> <mn>18</mn> <mi> </mi> <mi>N</mi> </math> </span></p>
Option 3 - <p><span class="mathml" contenteditable="false"> <math> <mn>180</mn> <mi> </mi> <mi>N</mi> </math> </span></p>
Option 4 - <p><span class="mathml" contenteditable="false"> <math> <mn>60</mn> <mi> </mi> <mi>N</mi> </math> </span></p>
6 Views|Posted 4 months ago
Asked by Shiksha User
1 Answer
A
4 months ago
Correct Option - 3
Detailed Solution:

From equation of uniformly accelerated motion

v = u + a t

7.5 = 15 + 5 a

a = - 1.5 m / s 2

n o w F = m a

F ? = 120 * 1.5

= 180 N

Thumbs Up IconUpvote Thumbs Down Icon

Taking an Exam? Selecting a College?

Get authentic answers from experts, students and alumni that you won't find anywhere else.

On Shiksha, get access to

66K
Colleges
|
1.2K
Exams
|
6.9L
Reviews
|
1.8M
Answers

Learn more about...

Physics Laws of Motion 2025

Physics Laws of Motion 2025

View Exam Details

Most viewed information

Summary

Share Your College Life Experience

Didn't find the answer you were looking for?

Search from Shiksha's 1 lakh+ Topics

or

Ask Current Students, Alumni & our Experts

Have a question related to your career & education?

or

See what others like you are asking & answering