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.
In: Physics
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.
In: Physics
|
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 . |
|
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 |
In: Physics
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
In: Physics
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.
In: Physics
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?
In: Physics
In: Physics
A)Why is the electrical resistivity of a thin film metal higher than its bulk value? Choose one.
- a) It experiences excessive surface oxidation - b) It has a lower work function - c) Dimensions of the film are comparable to the mean free path
- d) a and b - e) b and c - f) a and b and c
B) Describe how electrical conduction occurs in a lithium polymer electrode?
C) Describe thermal conduction in metals and how it differs from thermal conduction in an insulator. d) What is drift mobility? If we have conduction by ion diffusion in an insulator, is the drift mobility large or small compared to that of a metal? Why?
D) What is drift mobility? If we have electrical conduction by ion diffusion in an insulator or polymeric system, is the drift mobility large or small compared to that of a metal? Why?
In: Physics
Two stones are dropped from the edge of a 60-m cliff, the second stone 2.0 s after the first. How far below the top of the cliff is the second stone when the separation between the two stones is 40 m?
In: Physics
Two ideal linear sheet polarizers are arranged with their transmission axes at 10 degrees and 60 degrees with respect to vertical.
a) If a beam of linearly polarized light with its electric field at 40 degrees with respect to vertical enters the first polarizer, what fraction of its
irradiance will emerge from the second?
b) Replace the polarized beam with a beam of natural, randomly polarized light. Now calculate the fraction of the incident irradiance that emerges
from the second polarizer.
In: Physics
A ceiling fan is turned on and reaches an angular speed of 120 rev/min in 50 sec. It is then turned off and coasts to a stop in 40 s. Find the total number of revolution made before the fan stops
In: Physics
Three point charges are aligned along the x axis.Three point charges lie along the x-axis in the x y coordinate plane. A charge of −4.00 nC is 0.500 m to the left of the origin. A charge of 5.00 nC is at the origin. A charge of 3.00 nC is 0.800 m to the right of the origin.
Find the electric field (in N/C) at the following positions.
(a) (4.00, 0)
(b) (0, 4.00)
In: Physics
A 45 kg figure skater is spinning on the toes of her skates at 1.0 rev/s . Her arms are outstretched as far as they will go. In this orientation, the skater can be modeled as a cylindrical torso (40 kg , 20 cm average diameter, 160 cm tall) plus two rod-like arms (2.5 kg each, 69 cm long) attached to the outside of the torso. The skater then raises her arms straight above her head, where she appears to be a 45 kg, 20-cm-diameter, 200-cm-tall cylinder.
What is her new rotation frequency, in revolutions per second?
In: Physics
Q.2.Two sinusoidal waves combining in a medium are described by the wave functions y1 = (0.3m ) cos (2πx +40πt) y2=( 0.3 m) sin (2πx +40πt ) (i). What will be the resultant displacement wave function expression and what type of the resultant wave will be generated by it. [3] (ii). What will be the amplitude, frequency and the speed of the resultant wave? [3] (iii).Find the transverse velocity and transverse acceleration at x= 0.25m, and t= 2sec?
In: Physics
a) A block ice of mass 1kg has a temperature of -5°C and gets placed in Calorimeter A, filled with 10l of water at a temperature of 15°C. Determine the temperature Teq at equilibrium.
b) An identical block of ice gets placed in calorimeter B, filled with 2l of water at a temperature of 15°C. Determine the amount of ice, Mice, left at equilibrium.
Cwater = 4190J/kg*K, Cice = 2100J/kg*K, Lf= 3.34*10^5 J/kg
In: Physics