Homework questions - Newton's Laws

AI Thread Summary
To solve the homework questions on Newton's Laws, start by drawing free body diagrams for each scenario. For the swing ride, identify the forces acting on the chair, focusing on tension and gravitational force, and apply the principles of circular motion to find the tension and speed. For the spinning chamber ride, use the centripetal force equation to relate the force felt by the person to the radius of the chamber. Understanding the balance of forces in both scenarios is crucial for solving the problems effectively. Properly applying these concepts will lead to the correct answers.
tbtheqt
Messages
1
Reaction score
0
(1)A "swing" ride at a carnival consists of chairs that are swung in a circle by 10.0 m cables attached to a vertical rotating pole at an angle of 60 degrees with respect to the pole. Suppose the total mass of a chair and its occupant is 200 kg. (a) Determine the tension in the cable attached to the chair. (b) Find the speed of the chair.

(2)At an amusement park there is a ride in which cylindrically shaped chambers spin around a central axis. People sit in seats facing the axis, their backs against the outer wall. At one instant the outer wall moves at a speed of 3.62 m/s, and an 88.9-kg person feels a 507-N force pressing against his back. What is the radius of a chamber?



ƩF=ma
a(centripetal)=v^2/r



Can anybody help me with how to start negotiating this problem? I'm not sure how to begin. I was taught to draw free body diagrams first but that doesn't seem to get me anywhere.
 
Physics news on Phys.org
welcome to physicsforums, tbtheqt!

Free body diagrams are the right method. Start with the first question. Write down the free body force diagram for the chair. and then the question tells you that the chair swings in a (horizontal) circle, so what does this tell you about the sum of the horizontal forces? And also, you know the chair does not accelerate vertically, so this tells you something about the sum of the vertical forces
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

Centripetal Force HW: Determine Tension & Speed of Chair
Replies
2
Views
2K
Applying Newton's laws to find forces
Replies
8
Views
14K
Tension of an Object Swinging in a Circle
Replies
1
Views
8K
Finding Tension using Newton's Laws
Replies
4
Views
3K
What is the Speed and Tension of a Swing Ride?
Replies
3
Views
7K
Determine the tension in the cable attached to the chair
Replies
1
Views
20K
Can Duct Tape Really Hold a Person Against a Wall?
Replies
1
Views
3K
Forces and centripital acceleration
Replies
2
Views
2K
Newtons laws, dynamics questions
Replies
1
Views
1K
What Are the Average Forces and Friction in These Motion Problems?
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top