1. Homework Class Example Variations Weekend homework
Physics 12-14
Homework
Class Example
Variations
Weekend homework

2. Questions from the handout titled “Section 5-2 Quiz” ?

3. Hand in the results
Teacher Edition of the new textbook is in

12. Do
Jimmy (whose mass is 49 kg) is being dragged up the slide by his sister, Tanya, with a force of 1800 N. The angle of inclination of the slide is 56°, and the coefficient of friction between boy and slide is 0.34
What is the net force on the boy?
What is the acceleration (if any) of the boy?

13. Free Body Diagram

14. Calculation of individual forces
Fsister
Fparallel
Fperpendicular
Fnormal
Ffriction

15. Calculation of net forces
Which way will the friction force be directed?

16. Calculation of the acceleration

17. Class-Homework Given out on 12-14
Show all steps
Draw a diagram
Units

18. Class-Homework
1) A 63 kg water skier is pulled up a 14° incline by a rope parallel to the incline with a tension of 512 N. The coefficient of friction of kinetic friction is What are the magnitude and direction of the skier’s acceleration?

19. Question 2
A 62 kg person on skis is going down a hill sloped at 37°. The coefficient of friction between ski and snow is How fast is the skier going 5.0 s after starting from rest ?

20. Question #3
Stacie, who has a mass of 45 kg, starts down a slide that is inclined at an angle of 45° with the horizontal. If the coefficient of kinetic friction between Stacie’s pants and the slide is 0.25, what is her acceleration?

21. Question #4
Kohana, who has a mass of 50.0 kg, is at the dentist’s office having her teeth cleaned. If the component of her weight perpendicular to the plane of the chair is 449 N, at what angle is the chair tilted?

22. Question #5
A crate weighing 562 N is resting on a plane inclined 30.0° above the horizontal. Find the components of the weight forces that are parallel and perpendicular to the plane.
IF the surface is smooth and the crate starts from rest, after seconds how fast will the crate be moving?

23. Answers 3.2 m/s2 [uphill] = a 23.6 m/s [downhill] = vf
5.2 m/s2 [downhill] = a
23.6° = θ
Fperp = 487 N, Fpara = 281 N
19.7 m/s [downhill]

24. Quiz on 2D force and motion Quiz Tomorrow
About 3 questions, no multiple choice
Combine forces
Determine acceleration (magnitude and direction)
Determine Vf, Vi, t or d
Work with objects on inclines

25. Review and Homework Not to be collected
1) A weight of 562 N starts from rest and slides down the frictionless incline. As it leaves the 30°, its speed is 24m/s.
a) What is the acceleration of the mass while on the incline?
b) What is the length of incline?
c) What is the time it takes to reach the floor

26. 2) 2 forces are applied to a 56 kg object on level ground
2) 2 forces are applied to a 56 kg object on level ground. Force A = 45 N [E 81 S] and Force B = 89 N [N 39 W]