Summary







































PoP5 4.27b
A car's accelerometer (consisting of a mass on a string) hangs θ = 23.0° from the vertical. What is the car's acceleration?
hanging mass not vertical due to acceleration
A. 3.83 m/s2
B. 4.16 m/s2
C. 15.6 m/s2
D. 23.1 m/s2
Answer



















PoP5 4.18 mod
A sea lion slides from rest down a frictionless 15.0° ramp that is 2.00 m long. What is its speed at the bottom?
sea lion sliding down ramp A. 0.536 m/s
B. 0.163 m/s
C. 6.26 m/s
D. 3.19 m/s
Answer



















HRW10e 5.87mod
When a person stands on a scale in an elevator that is at rest, the scale reads 755 N. What does the scale read when the elevator accelerates downward at 2.20 m/s²?
person standing on scale in elevator A. 169 N
B. 585 N
C. 755 N
D. 924 N
Answer



















klm
A 4.54-kg bag of French fries (?) hangs from a clothesline, each side of which makes an angle θ = 15.0° from the horizontal. What is the tension in the clothesline?
hanging mass on a clothesline A. 11.5 N
B. 44.5 N
C. 86.0 N
D. 332 N
Answer



















PoP5 4.26b
A 10.0-kg load is suspended by three cords as shown. What is the tension in the strand of cord labeled T1?
figure P4.24 A. 98.0 N
B. 113 N
C. 196 N
D. 339 N
Answer



















wk4
Two canoes meet in the middle of a lake. After a brief visit, a person in canoe 1 (m1 = 100 kg) pushes on canoe 2 (m2 = 200 kg) and in turn gets pushed. How are the magnitudes of the two forces related? Walker4 Example 5-3
A. F1 = F2
B. F1 = ½F2
C. F1 = 2F2
D. F1 = 4F2
Answer



















PoP5 4.36
Two masses of m1=11.0 kg and m2=16.0 kg are connected as shown. What will their acceleration be? See also the interactive applet.
A. 3.06 m/s2
B. 0.265 m/s2
C. 1.81 m/s2
D. 9.80 m/s2
Answer







































answer

B. 4.16 m/s2
solution equation



















answer
sea lion sliding down ramp
D. 3.19 m/s
solution equation



















answer
person standing on scale in elevator
B. 585 N
The person's mass is m = W/g = (755 N)/(9.80 m/s²) = 77.0 kg, and the scale reads the amount of the normal force acting on the person.
Newton's second law (in the vertical direction) for the person reads +FN −mg = ma. Hence the scale will read:
FN = ma + mg = (77.0 kg)(−2.20 m/s² + 9.80 m/s²) = 585 N



















answer
hanging mass on a clothesline
C. 86.0 N

solution equation



















answer

B. 113 N
solution equation















 



A. F1 = F2

Action/reaction forces are always equal in magnitude and opposite in direction.
























answer

C. 1.81 m/s2