A roller coaster car with a mass 700 Kilograms starts from rest at h1 above the ground and slides along a track. The car encounters a loop of radius 12 m. The bottom of the loop is a height h2 = 5 m from the ground. What would be the max height of release h1 for the roller coaster car if the amount of thermal energy produced between the point of release and the top of the loop should not exceed 15% of the initial mechanical energy and the normal force at the top should be no more than 580 N? answer in meters
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1 (a) . Show that the zero-point energy of a Debye solid composed of N atoms is equal to 9/8NkΘD. This implies, for each vibrational mode of the solid, a mean zero-point energy 3/8 kΘD, that is, = 3/4 ωD.
(b)Show that, for T < θd,="" the="" quantity="">P − CV) of a Debye solid varies as T7 and hence the ratio (CP/CV) 1
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What is the correct line of thinking in dealing with a statics problem where one must determine the resultant force from multiple vectors using a unit triangle instead of cos and sin; ie. how do you use a unit triangle?
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Two bicycle tires are set rolling with the same initial speed of 3.70 m/s along a long, straight road, and the distance each travels before its speed is reduced by half is measured. One tire is inflated to a pressure of 40 psi and goes a distance of 17.8 m ; the other is at 105 psi and goes a distance of 93.3 m . Assume that the net horizontal force is due to rolling friction only and take the free-fall acceleration to be g = 9.80 m/s2 .
a)What is the coefficient of rolling friction μr for the tire under low pressure?
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A bullet of mass m=14 gr is fired into a block of mass M=1 kg initially at rest at the edge of a frictionless table of height h=1.10 m. The bullet remains in the block and the block lands a distance d=0.65 m from the bottom of the table.
Determine the initial velocity of the bullet.
Determine the loss of kinetic Energy during the collision
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A bullet of mass m=12 gr is fired into a block of mass M=1 kg initially at rest at the edge of a frictionless table of height h=1.00 m. The bullet remains in the block and the block lands a distance d=0.60 m from the bottom of the table. a)Determine the initial velocity of the bullet. vi= m/s b) Determine the loss of kinetic energy during the collision. ΔK = J
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A proton is traveling horizontally to the right at 4.00×106 m/s. (a) Find the magnitude and direction of the weakest electric field that can bring the proton uniformly to rest over a distance of 1.67 cm. (b) How 7 much time does it take the proton to stop after entering the field?A −1.00-nC point charge is at the origin, and a +4.00-nC point charge is on the y-axis at y = 2.00 m. (a) Find the electric field (magnitude and direction) at each of the following points on the y-axis: (i) y = 3.00 m; (ii) y = 1.00 m; (iii) y = −2.00 m. (b) Find the net electric force that the two charges would exert on an electron placed at each point in part (a).
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A bullet of mass m=20 gr is fired into a block of mass M=5 kg initially at rest at the edge of a frictionless table of height h=0.90 m. The bullet remains in the block and the block lands a distance d=0.68 m from the bottom of the table. Picture1 a)Determine the initial velocity of the bullet. vi= m/s b) Determine the loss of kinetic Energy during the collision. ΔK = J.
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A bullet of mass m=11 gr is fired into a block of mass M=1 kg initially at rest at the edge of a frictionless table of height h=1.10 m. The bullet remains in the block and the block lands a distance d=0.67 m from the bottom of the table.
a)Determine the initial velocity of the bullet.
b) Determine the loss of kinetic Energy during the collision.
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On an average winter day (3 or 38 ) in a typical house, energy already in the house is lost at the following rates: (i) 2.1 is lost through partially insulated walls and the roof by conduction; (ii) 0.3 is lost through the floor by conduction; and (iii) 1.9 is lost by conduction through the windows. Additional heating is also needed at the following rates: (iv) 2.3 to heat the air infiltrating the house through cracks, flues, and other openings and (v) 1.1 to humidify the incoming air (because warm air must contain more water vapor than cold air for people to be comfortable). On the same day in the same house some thermal energy is supplied by heating in the following amounts: (i) sunlight through windows, 0.5 ; (ii) thermal energy given off by the inhabitants, 0.2 ; and (iii) thermal energy from appliances, 1.2 . |
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Part A Suppose that the following design changes are made to the house described above: (i) additional insulation of walls, roof, and floors, cutting thermal losses by 60 ; (ii) tightly fitting double- glazed windows with selective coatings to reduce the passage of infrared light, cutting conduction losses by 70 ; and (iii) elimination of cracks, closing of flues, and so on, cutting infiltration losses by 70 . What is the total rate at which energy is lost from this house? Express your answer to two significant figures and include the appropriate units. ANSWER: = -2.6 Please show how to get to answer per professor answer is -2.6 kW |
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A ball of mass m1 =5.2 kg and a block of mass m2 =2.0 kg are
connected with a lightweight string over a pulley with moment of
inertia I and radius R=0.25m. The coefficient of kinetic friction
between the table top and the block of mass m2 is μk = 0.4. If the
magnitude of the acceleration is a=2.7 m/s2.
torque_rotational
a)What are the tensions T1 and T2 in the string.
T1=
N
T2=
N
b)Calculate the moment of inertia of the pulley.
I=
kg m2
c) What is the change of the kinetic energy of the system if the
system is released from rest and the ball decends a distance h=7.9
m downward.
ΔK =
J
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In some video games, spacecraft employ ion drives. Write a
report discussing how an ion drive operates and whether it can
efficiently propel a spacecraft. You will be marked on how well you
explain scientific principles and the accuracy of your statements.
Your report should be understandable by nonscientists.
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a steel ring with a 2.500 in diameter at 20 degrees
Celsius is to he warned and slipped over a brass shafts with a
2.5030in outside diameter at 20 degrees Celsius
To what temperature should the ring be warmed?
if the ring and the shaft together are cooled by some means such as
liquid air, at what temperature will the ring just slip off the
shaft?
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