# Newtons second law about momemtum

• Nickles
In summary, the problem involves a 10kg mass initially at rest and acted on by a force of 10N for 10 seconds. Using the equation F=change in momentum/time, the final velocity of the mass is determined to be 10 m/s. However, the book's answer of 20 m/s may be incorrect, as it is inconsistent with the problem and the approach used. To confirm the answer, another method of solving the problem, such as finding the acceleration and using kinematics, can be used.
Nickles

## Homework Statement

a mass of 10kg, initially at rest, is acted on by a force of 10N for 10 s. What is the final velocity of the mass?

## Homework Equations

i think this equation should help: F= change in momentum/ time

## The Attempt at a Solution

hey everyone i am out of school so far for the summer but i love physics so much thta i want to self study it over the entire summer and so far so god butr i can't get this problem. please help me.

i tried using the formual above and here ARE MY STEPS

F= mv-mu/ t

10N= {10kgx V- 10kg x 0 m/s) / 10s
10= 10kg x V- 0/ 10s
10N x 10s= 10 x v
100/10= 10
v= 10

but my book says the answer is 20 m/s as the answer and i have no idea how they arrived at this answer, i am not really that good AT QUESTIONS LIKE THIS BUT I LOVE P[HYSICS SO MUCH THAT I AM WILLING TO LEARN SO any help will be truly appreciated . i think i might be using the wrong formula.

Your answer is correct; the book's is not. (Hopefully you have the right problem.)

yes it is the same question in the book and i double checked, but this book is so consistent and is written by top examination setters in the carribbean and head of physics department at the top college in my country. i know that they too can make mistakes but i want to be truly sure that i have the correct answer or if i made a mistake

Nickles said:

## Homework Statement

a mass of 10kg, initially at rest, is acted on by a force of 10N for 10 s. What is the final velocity of the mass?

## Homework Equations

i think this equation should help: F= change in momentum/ time

## The Attempt at a Solution

hey everyone i am out of school so far for the summer but i love physics so much thta i want to self study it over the entire summer and so far so god butr i can't get this problem. please help me.

i tried using the formual above and here ARE MY STEPS

F= mv-mu/ t

10N= {10kgx V- 10kg x 0 m/s) / 10s
10= 10kg x V- 0/ 10s
10N x 10s= 10 x v
100/10= 10
v= 10
but my book says the answer is 20 m/s as the answer and i have no idea how they arrived at this answer, i am not really that good AT QUESTIONS LIKE THIS BUT I LOVE P[HYSICS SO MUCH THAT I AM WILLING TO LEARN SO any help will be truly appreciated . i think i might be using the wrong formula.

Remember to label the units as I know teachers who take off points for not labeling. Plus you should get into the habit of doing so.

WOOT 100 POST COUNT!!!!!

Last edited:
Nickles said:
yes it is the same question in the book and i double checked, but this book is so consistent and is written by top examination setters in the carribbean and head of physics department at the top college in my country. i know that they too can make mistakes but i want to be truly sure that i have the correct answer or if i made a mistake
To convince yourself that your answer is correct, try solving it in a different way. For example: Find the acceleration of the mass, then use kinematics.

## What is Newton's Second Law of Momentum?

Newton's Second Law of Momentum states that the force applied to an object is equal to the mass of the object multiplied by its acceleration. In other words, the greater the mass of an object, the more force is required to accelerate it.

## How is momentum defined in Newton's Second Law?

Momentum is defined as the product of an object's mass and velocity. This means that an object with a larger mass or a higher velocity will have a greater momentum.

## How does Newton's Second Law relate to the concept of inertia?

Newton's Second Law relates to the concept of inertia by stating that an object at rest will remain at rest unless acted upon by an external force. This is because objects with greater mass have more inertia and are more resistant to changes in motion.

## Can Newton's Second Law be applied to both linear and rotational motion?

Yes, Newton's Second Law can be applied to both linear and rotational motion. In linear motion, the force is applied in a straight line, while in rotational motion, the force is applied at a distance from the center of rotation.

## How does Newton's Second Law contribute to our understanding of motion and forces?

Newton's Second Law is an important principle in physics as it explains the relationship between motion and forces. It helps us understand how forces can change an object's motion and how different factors such as mass and velocity impact an object's momentum.

Replies
6
Views
1K
Replies
42
Views
4K
Replies
3
Views
1K
Replies
44
Views
2K
Replies
5
Views
2K
Replies
15
Views
596
Replies
15
Views
2K
Replies
13
Views
2K
Replies
17
Views
772
Replies
8
Views
993