Answer:
the image is virtual and erect and the lens divergent; therefore the correct answer is C
Explanation:
In a thin lens the magnification given by
m = h '/ h = - q / p
where h ’is the height of the image, h is the height of the object, q is the distance to the image and p is the distance to the object.
It indicates that the object is straight and is placed at a distance p> f
analyze the situation tells us that the magnification is positive so the distance to the image must be negative, that is, that the image is on the same side as the object.
Consequently the lens must be divergent
The magnification value is
0.4 = h ’/ h
h ’= 0.4 h
therefore the erect images
therefore the image is virtual and erect and the lens divergent; therefore the correct answer is C
Answer:t=5.07 s
Explanation:
Given
height of Building h=18 m
mass of Paint can 
mass of second can 
let T be the Tension in the rope
For 4 kg can

----1
For 3 kg can

----2
From 1 and 2



So time taken to cover 18 m is




Answer:
W
Explanation:
= Temperature of the room = 22.0 °C = 22 + 273 = 295 K
= Temperature of the skin = 33.0 °C = 33 + 273 = 306 K
= Surface area = 1.50 m²
= emissivity = 0.97
= Stefan's constant = 5.67 x 10⁻⁸ Wm⁻² K⁻⁴
Rate of heat transfer is given as


W
Answer:
4.41 W
Explanation:
P = IV, V = IR
P = V² / R
Given that P = 0.0625 when V = 1.50:
0.0625 = (1.50)² / R
R = 36
So the resistor is 36Ω.
When the voltage is 12.6, the power consumption is:
P = (12.6)² / 36
P = 4.41
So the power consumption is 4.41 W.
Answer:
a. The temperature of the copper changed more than the temperature of the water.
Explanation:
Because we're only considering the isolated system cube-water, the heat of the system should be constant, that implies the heat the cube loses is equal the heat the water gains (because by zero law of thermodynamics heat (Q) flows from hot body to cold body until reach thermal equilibrium and T1>T2). So:
(1)
But Q is related with mass (m), specific heat (c) and changes in temperature (
)in the next way:
(2)
Using (2) on (1):



Because we have an equality and 0.385 < 4.186 then
to conserve the equality