Newtons second law about momemtum

[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.

 

[Doc Al]

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

 

[Nickles]

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

 

[BloodyFrozen]

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!!!!!

 

[Doc Al]

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.