Grade 12 Physics help, Kinematics

[Telmob]

Homework Statement

Alright, just started physics and I've already fallen behind :(

trying to do my homeowkr and I am completely lost, no idea at all.

So here's a question which i had no idea how to do.

* A tree house has a vertical "fire pole" of smooth metal, designed for quick exits. A child of mass 35.7Kg slides down the pole with constant acceleration, starting from rest. The pole is 3.10m high. The journey to the ground takes 2.00s.
a) what is the magnitude of the downward acceleration of the child?
b) What is the magnitude of the upward force of friction exerted by the pole of the child?

Also, i looked in the back of my textbook and in my notes, and i still don't know what magnitude means. Or how to get it for that matter.

Homework Equations

I know for this problem to find a) i could use the equation a= external friction/mass
but how do i find a? is it just g= -9.8m/s² or does it have to do with the kids weight?
and i have no idea how to get the external friction or what exactly it is.

I know this right now
m=35.7Kg
T= 2s
Height= 3.1m high
g= -9.8m/s²


i don't know if this is enough information but please help me, its been 2 weeks and I am already behind, I've gone to extra help after school, but its the same teacher and i guess i just don't understand him.

 

[learningphysics]

For the first part don't use forces... just use kinematics. You can immediately calculate acceleration by using the right equation.

 

[m2003]

Dear student,

I can understand your frustration and feeling of falling behind in your physics class. Kinematics can be a challenging topic, but with some practice and understanding of the concepts, I am sure you will be able to catch up and excel in this subject.

Firstly, let me explain what magnitude means. In physics, magnitude refers to the size or amount of a physical quantity. For example, the magnitude of a force is its strength or intensity. In the given problem, we need to find the magnitude of the downward acceleration and the upward force of friction.

To find the magnitude of the downward acceleration (a), we can use the equation a = (vf - vi)/t, where vf is the final velocity, vi is the initial velocity (which is zero in this case), and t is the time taken. We are given the time (2.00s) and the height (3.10m) in the problem. Using the equation, we can find the final velocity of the child at the bottom of the pole. Then, we can use the equation vf^2 = vi^2 + 2ad to find the acceleration (a).

To find the magnitude of the upward force of friction, we need to understand that friction is a force that opposes motion and it acts in the opposite direction of the motion. In this case, the child is sliding down the pole, so the frictional force will act upward. The magnitude of this force can be found using the equation Ff = μN, where μ is the coefficient of friction and N is the normal force. The normal force in this case is equal to the weight of the child (mg). The coefficient of friction depends on the surface and the materials in contact. If the pole is smooth, the coefficient of friction will be very low.

I hope this helps you with your homework problem. Remember to always read the question carefully and identify the given information and what is being asked. Practice using the equations and make sure you understand the concepts behind them. If you are still having trouble, don't hesitate to ask your teacher or seek additional help from a tutor. Keep up the hard work and don't give up. I am sure you will do well in your physics class. All the best!