落第什么意思Kinematics
1. What is the angular displacement of each of the following hands of a clock in 1 h?
State your answer in three significant digits.(a). the cond hand .(b). the minute hand .(c). the hour hand.
sharapova2. A rotating toy above a baby’s crib makes one complete
counterclockwi rotation in 1 min.
A. What is its angular displacement in 3 min ?
B.What is the toy’s angular
velocity in rad/min ?
C.If the boy is turned off, does it have positive or negative angular acceleration ? Explain .
3.If a truck has a linear acceleration of 1.85 m/s2 and the wheels have an angular acceleration of 5.23 rad/s2, what is the diameter of the truck’s wheels?
4. The truck in the previous problem is towing a trailer with wheels that have
a diameter of 48 cm.
a. How does the linear acceleration of the trailer compare with that of the truck?
b. How do the angular accelerations of the wheels of the trailer and the wheels of the truck compare?
5. You want to replace the tires on your car with tires that have a larger diameter. After you
change the tires, for trips at the same speed and over the same distance, how will the
angular velocity and number of revolutions change?
6.If the radius of a CD is 6.0 cm and the angular velocity is 5.0 rad/s . What is the linear displacement of a point on the edge is 2.0 s ?
(A). 0.30 m (B). 0.60 m (C). 3.8 m (D). 60 m
Torque
1. A door (en from above in the figures below) has hinges on the left hand
scauside. Which force produces the largest torque? The magnitudes of all forces are equal.
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2.A rod on a horizontal tabletop is pivoted at one end and is free to rotate without friction about a vertical axis, as shown. A force F is applied at the other end, at an angle to the rod. If F were to be applied perpendicular to the rod, at what distance from the axis should it be applied in order to prod uce the same torque?
(A) L sin (B) L cos (C) L (D) L tan
3.In which of the following diagrams is the torque about point O equal in包罗万象英语
magnitude to the torque about point X in the diagram? (All forces lie in the plane of the paper.)
4. A 5‑meter uniform plank of mass 100 kilograms rests on the top of a building with 2 meters extended over the edge as shown. How far can a
50‑kilogram person venture past the edge of the building on the plank before the plank just begins to tip?
udto(A) 0.5 m (B) 1 m (C) 1.5 m ( D) 2 m
5. A uniform meterstick of mass 0.20 kg is pivoted at the 40 cm mark.
on the way什么意思Where should one hang a mass of 0.50 kg to balance the stick?
(A) 16 cm (B) 36 cm (C) 44 cm (D) 46 cm
actor的动词
6. To weigh a fish, a person hangs a tackle box of mass 3.5 kilograms and
a cooler of mass 5 kilograms from the ends of a uniform rigid pole that
is suspended by a rope attached to its center. The system balances when the fish hangs at a point 1/4 of the rod’s length from the tackle box.
What is the mass of the fish?evolution
(A) 1.5 kg (B) 2 kg (C) 3 kg (D) 6 kg
7.Two objects, of mass 6 and 8 kilograms, are hung from the ends of a stick that is 70 cm long and has marks every 10 cm, as shown. If the mass of the
ydm
stick is negligible, at which of the points indicated should a cord be attached if the stick is to remain horizontal when suspended from the cord?
(A) A (B) B (C) C (D) D
8.A square piece of plywood on a horizontal tabletop is subjected to the two
horizontal forces shown. Where should a third force of magnitude 5
newtons be applied to put the piece of plywood into equilibrium?
