Physics Heat & Thermodynamics Level: High School
23.3 degree zero on the Fahrenheit scale is what Celsius temperature ?
Physics Heat & Thermodynamics Level: High School
23.3 degree below zero on the Celsius scale is what Fahrenheit temperature ?
Physics Ray Optics Level: High School
A small insect viewed through a convex lens is 2.3 cm from the lens and appears twice its actual size .Part A):What is the focal length of the lens?
Express your answer using two significant figures . f= cm
Physics Ray Optics Level: High School
A lens for a 41 mm camera has a focal length given by f = 53 mm .Part A): How close to the film should the lens be placed to form a sharp image of an object that is 4.2 m away?
Express your answer using two significant figures. di= mm
Part B): What is the magnification of the image on the film?
Express your answer using two significant figures. m=?
Physics Ray Optics Level: High School
When an object is located 43 cm to the left of a lens, the image is formed 26 cm to the right of the lens .What is the focal length of the lens?
Express your answer using two significant figures .
f= cm
Physics Ray Optics Level: High School
A concave lens has a focal length of -36 cm . Find the image distance and magnification that results when an object is placed 28 cm in front of the lens .Part (A)Express your answer using two significant figures .
di= cm
Part (B) Express your answer using two significant figures . m=?
Physics Ray Optics Level: High School
A coin is lying at the bottom of a pool of water that is 7.3 feet deep .Viewed from directly above the coin , how far below the surface of the water does the coin appear to be ? (The coin is assumed to be small in diameter ; therefore , we can use the small angle approximations sinć ~ tanć ~theta .)
Express your answer using two significant figures.
dapp = ft
Physics Ray Optics Level: High School
The angle of refraction of a ray of light traveling through an ice cube is 30 degrees . Suppose the ice melts , but the angle of refraction remains the same .Part A) Is the corresponding angle of incidence greater than , less than , or the same as it was for ice ? Why?
Part B) Calculate the angle of incidence for part A . theta i= degrees
Physics Ray Optics Level: High School
The angle of refraction of a ray of light traveling through an ice cube is 30 degrees .Express your answer using two significant figures .
Find the angle of incidence
ći= degrees
Physics Ray Optics Level: High School
The virtual image produced by a convex mirror is one-quarter the size of the object .Part A) If the object is 40 cm in front of the mirror , what is the image distance ?
Express your answer using two significant figures . di=?cm
Part B) What is the focal length of this mirror? Express your answer using two significant figures . f=?cm
Physics Ray Optics Level: High School
A magician wishes to create the illusion of a 3.56m tall elephant . He plans to do this by forming a virtual image of a 52.0 cm tall model elephant with the help of a spherical mirror .A) Should the mirror be concave or convex? Why
B) If the model must be placed 3.15 m from the mirror, what radius of curvature is needed? R=?
C) How far from the mirror will the image be formed
di= ?m
Physics Heat & Thermodynamics Level: High School
If a natural gas costs 0.084 dollar per kilogram and its heat of combustion is 5.40 x 10^7 J/kg , how much is the monthly cost (in dollar) to maintain the house at a temperature of 23.0 degreeC for 24 hr each day assuming 88.3 percent of the heat produced is used to heat the house .
Physics Heat & Thermodynamics Level: High School
If the house is initially at 11.2 degreeC , estimate how much heat must be supplied to raise the temperature to 23.0 degreeC within 33.0 min . Assume that only the air needs to be heated and that its volume is 707 m^3 . Take the specific heat of air to be 0.24 kcal/kgC .
Physics Heat & Thermodynamics Level: High School
A house has a well-insulated walls 17.7 cm thick (assume conductivity of air)and area 409 m^2 , a roof of wood 6.75 cm thick and area 281 m^2 . and uncovered windows 0.614 cm thick and total area 33.1m^2. Assuming that the heat loss is only by conduction , calculate the rate at which heat must be supplied to this house to maintain its temperature at 23.0 degreeC if the outside temperature is -10.5 degreeC .
Physics Heat & Thermodynamics Level: High School
During light activity , a 70.5 kg person may generate 195 kcal/hr . Assuming that 20.3 percent of this goes into useful work and the other 79.7 percent converted to heat , calculate the temperature (in degreeC) rise of the body after 1.05 hr if none of this heat were transferred to the environment