Vincent Nilio
Chapter 7 Lab Activity
Lunar Lander Simulation
1.
a) After reaching an altitude above 250m and tilting the LM to 45 and then giving it a quick burst of
full throttle, the x-Velocity vector (green vector) points in the direction of the accele
You can stop a mosquito travelling at a certain speed towards you by intercepting it with your
hand. Can you do the same for a car moving at the same speed as a mosquito? Discuss this
scenario using your knowledge on momentum and impulse. Give examples of
Discuss the features of dead-sea in terms of buoyancy, density, and general fluid mechanics
knowledge. If you were to reverse the properties of dead-sea, what could you do?
The Archimedes Principle says that when an object is completely or partially immer
A man walking on a tightrope carries a long a pole which has heavy items attached to the two
ends. If he were to walk the tight-rope with just a pole, what difference would it make to his
balance? Discuss this in terms of angular rotation, angular momentu
Physics, 6th Edition
Chapter 6 Uniform Acceleration
*6-61. An arrow is shot upward with a velocity of 40 m/s. Three seconds later, another arrow is
shot upward with a velocity of 60 m/s. At what time and position will they meet?
Let t1 = t be time for fir
Physics, 6th Edition
Chapter 6 Uniform Acceleration
*6-59. A ball is dropped from rest at the top of a 100-m tall building. At the same instant a
second ball is thrown upward from the base of the building with an initial velocity of 50
m/s. When will the
Physics, 6th Edition
Chapter 6 Uniform Acceleration
*6-63. A wild boar charges directly toward a hunter with a constant speed of 60 ft/s. At the
instant the boar is 100 yd away, the hunter fires an arrow at 300 with the ground. What
must be the velocity o
Physics, 6th Edition
Chapter 5 Torque and Rotational Equilibrium
5-3. Determine the moment arm if the axis of rotation is at point A in Fig. 5-11b. What is the
F
magnitude of the moment arm?
rB = (2 m) sin 60
0
600
rB = 1.73 m
B
300
2m
A
38
5m
rA
rB
Physics, 6th Edition
Chapter 5 Torque and Rotational Equilibrium
5-1. Draw and label the moment arm of the force F about an axis at point A in Fig. 5-11a. What
is the magnitude of the moment arm?
rA
Moment arms are drawn perpendicular to action line:
A
rA
Physics, 6th Edition
Chapter 5 Torque and Rotational Equilibrium
5-6. The force F in Fig. 5-11b is 400 N and the angle iron is of negligible weight. What is the
resultant torque about axis A and about axis B?
Counterclockwise torques are positive, so that
Physics, 6th Edition
Chapter 5 Torque and Rotational Equilibrium
5-10. A single belt is wrapped around two pulleys. The drive pulley has a diameter of 10 cm,
and the output pulley has a diameter of 20 cm. If the top belt tension is essentially 50 N at
the
Physics, 6th Edition
Chapter 5 Torque and Rotational Equilibrium
5-12. Find the resultant torque in Fig. 5-13, if the axis is moved to the left end of the bar.
= +(30 N)(0) + (15 N)(4 m) - (20 N)(9 m)
15 N
A 4m
2m
3m
= -120 N m, counterclockwise.
30 N
4
Physics, 6th Edition
Chapter 5 Torque and Rotational Equilibrium
5-11. What is the resultant torque about point A in Fig. 5-13. Neglect weight of bar.
= +(30 N)(6 m) - (15 N)(2 m) - (20 N)(3 m)
15 N
4m
= 90.0 N m, Counterclockwise.
30 N
46
3m
2m
A
20 N
Physics, 6th Edition
Chapter 5 Torque and Rotational Equilibrium
5-5. If the force F in Fig. 5-11a is equal to 80 lb, what is the resultant torque about axis A
neglecting the weight of the rod. What is the resultant torque about axis B?
Counterclockwise t
Physics, 6th Edition
Chapter 5 Torque and Rotational Equilibrium
5-7. A leather belt is wrapped around a pulley 20 cm in diameter. A force of 60 N is applied to
the belt. What is the torque at the center of the shaft?
r = D = 10 cm;
= (60 N)(0.10 m) = +6
Physics, 6th Edition
Chapter 5 Torque and Rotational Equilibrium
5-8. The light rod in Fig. 5-12 is 60 cm long and pivoted about point A. Find the magnitude and
sign of the torque due to the 200 N force if is (a) 900, (b) 600, (c) 300, and (d) 00.
= (200
Physics, 6th Edition
Chapter 5 Torque and Rotational Equilibrium
5-9. A person who weighs 650 N rides a bicycle. The pedals move in a circle of radius 40 cm. If
the entire weight acts on each downward moving pedal, what is the maximum torque?
= (250 N)(0
Physics, 6th Edition
Chapter 6 Uniform Acceleration
*6-63. A wild boar charges directly toward a hunter with a constant speed of 60 ft/s. At the
instant the boar is 100 yd away, the hunter fires an arrow at 300 with the ground. What
must be the velocity o
Physics, 6th Edition
Chapter 6 Uniform Acceleration
*6-60. A balloonist rising vertically with a velocity of 4 m/s releases a sandbag at the instant
when the balloon is 16 m above the ground. Compute the position and velocity of the
sandbag relative to th
Physics, 6th Edition
Chapter 6 Uniform Acceleration
*6-62. Someone wishes to strike a target, whose horizontal range is 12 km. What must be the
velocity of an object projected at an angle of 350 if it is to strike the target. What is the
time of flight?
y
Physics, 6th Edition
Chapter 6 Uniform Acceleration
*6-41. The projectile in Problem 6-40 rises and falls, striking a billboard at a point 8 m above
the ground. What was the time of flight and how far did it travel horizontally.
vox = (35 m/s) cos 320 = 2
Physics, 6th Edition
Chapter 6 Uniform Acceleration
6-43. A railroad car starts from rest and coasts freely down an incline. With an average
acceleration of 4 ft/s2, what will be the velocity after 5 s? What distance does it travel?
vf = vo + at = 0 + (4
Physics, 6th Edition
Chapter 6 Uniform Acceleration
*6-44. An object is projected horizontally at 20 m/s. At the same time, another object located
12 m down range is dropped from rest. When will they collide and how far are they
B
A
located below the rele
Physics, 6th Edition
Chapter 6 Uniform Acceleration
6-42. A rocket travels in space at 60 m/s before it is given a sudden acceleration. Its velocity
increases to 140 m/s in 8 s, what was its average acceleration and how far did it travel in
this time?
a
s
Physics, 6th Edition
Chapter 6 Uniform Acceleration
6-45. A truck moving at an initial velocity of 30 m/s is brought to a stop in 10 s. What was the
acceleration of the car and what was the stopping distance?
a
s
v f v0
t
v0 v f
2
t
0 - 30 m / s
;
10 s
a
Physics, 6th Edition
Chapter 6 Uniform Acceleration
6-46. A ball is thrown vertically upward with an initial velocity of 23 m/s. What are its
position and velocity after 2s, after 4 s, and after 8 s?
Apply s = vot + at2 and vf = vo + at
for time of 2, 4,
Physics, 6th Edition
Chapter 6 Uniform Acceleration
6-48. A ball is thrown vertically upward with an initial velocity of 80 ft/s. What are its
position and velocity after (a) 1 s; (b) 3 s; and (c) 6 s
Apply s = vot + at2 and vf = vo + at
for time of 2, 4,
Physics, 6th Edition
Chapter 6 Uniform Acceleration
*6-50. In Problem 6-49, what was the horizontal range of the package and what are the
components of its final velocity?
vo = 500 mi/h = 733 ft/s;
vx = vox = 733 ft/s;
x = vxt = (733 ft/s)(4 s);
vy = voy
Physics, 6th Edition
Chapter 6 Uniform Acceleration
6-47. A stone is thrown vertically downward from the top of a bridge. Four seconds later it
strikes the water below. If the final velocity was 60 m/s. What was the initial velocity of
the stone and how h