# Math Help - newton's fundamental laws

1. ## newton's fundamental laws

A puck of mass 30g slides across rough ice, experiencing a frictional force of 0.2N. If it was moving at 10 km/h when it hit the ice patch,

a) how long did it take to stop?
i first calculated the acceleration of the puck and i got 6.66m/s^2. then i determined the time and i got 1.5 s

b) how long was the ice patch?
i used the time calculated in part a and got the answer 2.08m

2. Originally Posted by checkmarks
A puck of mass 30g slides across rough ice, experiencing a frictional force of 0.2N. If it was moving at 10 km/h when it hit the ice patch,

a) how long did it take to stop?
i first calculated the acceleration of the puck and i got 6.66m/s^2. then i determined the time and i got 1.5 s

b) how long was the ice patch?
i used the time calculated in part a and got the answer 2.08m

Fnet = ma => -0.2 = (0.03) a => a = .....

Now apply the usual formulae for straight line motion under constant acceleration, using the data:

a) u = 10km/hr = .... m/s (you know why the conversion from km/hr to m/s is required and how to do it, right?)
v = 0 m/s
a = ...
t = ?

b) u = 10km/hr = .... m/s
v = 0 m/s
a = ...
x = ?

3. ## Good textbook for study physics

I use the textbook

Conceptual Physics
Rainyland(Cocomartini) BookStore -University Textbooks Campus Reference Books - Book Details

to study the fundemental physics. I believe that will also useful for you to study physics

4. Originally Posted by checkmarks
A puck of mass 30g slides across rough ice, experiencing a frictional force of 0.2N. If it was moving at 10 km/h when it hit the ice patch,

a) how long did it take to stop?
i first calculated the acceleration of the puck and i got 6.66m/s^2. then i determined the time and i got 1.5 s

b) how long was the ice patch?
i used the time calculated in part a and got the answer 2.08m

The biggest thing I want to impart on you is this...in High School Physics...each chapter there is one formula that EVERYTHING is bulit off of...every problem is a derivation of that original formula...obviously for the chapter you are currently on it is $F=ma$...but for mechanical kinetic engery it is $Ke_1+U_{g_1}=Ke_2+U_{g_2}$...identify that formula each chapter and all the problems become easier
The biggest thing I want to impart on you is this...in High School Physics...each chapter there is one formula that EVERYTHING is bulit off of...every problem is a derivation of that original formula...obviously for the chapter you are currently on it is $F=ma$...but for mechanical kinetic engery it is $Ke_1+U_{g_1}=Ke_2+U_{g_2}$...identify that formula each chapter and all the problems become easier