Answer:
The power of the corrective lenses is 3.162 D.
Explanation:
Given that,
Object distance = 70 cm
Image distance = 62 cm
Distance between eyes and glasses = 2.5 cm
Eyeglasses made of diverging corrective lenses can help her to see the apple clearly
So now ,
Object distance from glass =70-2.5 = 67.5 cm
Image distance from glass = 62-2.5 = 59.5 cm
We need to calculate the focal length
Using formula for focal length
We need to calculate the power of lens
Using formula of power
Negative sign shows the lens is diverging.
Hence, The power of the corrective lenses is 3.162 D.
Answer:
R=V/I=6/2=3ohm
time =5minutes =5*60=300seconds
I=2A
Heat =I^2Rt=(2)^2*3*300=4*900=3600J
Answer:
Q = 40.1 degrees
Explanation:
Given:
- The weight of the timber W = 670 N
- Water surface level from pivot y = 2.1 m
- The specific density of water Y = 9810 N / m^3
- Dimension of timber = (0.15 x 0.15 x 0.0036) m
Find:
- The angle of inclination Q that the timber makes with the horizontal.
Solution:
- Calculate the Flamboyant Force F_b acting upwards at a distance x along the timber, which is unknown:
F_b = Y * V_timber
F_b = 9810*0.15*0.15*x
F_b = 226.7*x N
- Take static equilibrium conditions for the timber, and take moments about the pivot:
(M)_p = 0
W*0.5*3.6*cos(Q) - x/2 * F_b*cos(Q) = 0
- Plug values in:
670*0.5*3.6 - x^2 * 0.5*226.7 = 0
x^2 = 1206 / 113.35
x = 3.26 m
- Now use the value of x and vertical height y to compute the angle of inclination to be:
sin(Q) = y / x
sin(Q) = 2.1 / 3.26
Q = sin^-1 (0.6441718)
Q = 40.1 degrees
Answer: Physical
Explanation: There are no changes being done to the salt. Think of it this way, if you dissolve the salt in water then boil the water completely, you will have the same salt you started with.
