Grade 12 Physics help, Kinematics

AI Thread Summary
The discussion revolves around a Grade 12 physics student struggling with kinematics, specifically calculating acceleration and understanding the concept of magnitude. The problem involves a child sliding down a 3.10m pole with a mass of 35.7kg and a time of 2.00s. To find the downward acceleration, the student is advised to use kinematic equations rather than focusing on forces. The concept of magnitude is clarified as the absolute value of a quantity, which is essential for solving the problem. The student is encouraged to seek further clarification on kinematic equations to catch up on the material.
Telmob
Messages
1
Reaction score
0

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

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

How to Solve a 100m Dash Kinematics Problem with Unknown Acceleration?
Replies
14
Views
4K
Forces Grade 12 Physics Question
Replies
5
Views
2K
[Grade 12 Physics] Circular/gravitational motion
Replies
21
Views
3K
Circular motion grade 12 physics
Replies
4
Views
2K
Newton's laws question [grade 12]
Replies
1
Views
3K
Building a Self-Contained Egg Tower Device: Grade 12 Physics ISU Project
Replies
12
Views
2K
The Diffraction Grating (Grade 12 Physics)
Replies
1
Views
2K
Grade 12 Physics: Banked Roads and Friction Analysis
Replies
2
Views
2K
Kinematics Problem: Finding Initial Velocity of a Basketball Thrown at an Angle
Replies
2
Views
2K
A grade 12 physics dynamics problem
Replies
2
Views
2K

Hot Threads

Recent Insights

Back
Top