Answer:
309 m
Explanation:
time apart = 0.8 s
speed of sound in air = 343 m/s
speed of sound in concrete = 3000 m/s
lets assume it time it takes to travel trough concrete = T
the time it takes to travel through air = T + 0.8 since they are 0.8 s apart
the distance traveled by both waves is the same, so we can equate the distance for both waves
distance = speed x time
- for concrete, distance = 3000 x T
- for air, distance = 343 x (T + 0.8)
now equating the two distance together we have
3000 x T = 343 x (T + 0.8)
3000T = 343T + 274.4
3000T - 343T = 274.4
T = 0.103 s
recall that distance = 3000 x T = 3000 x 0.103 = 309 m
Answer:
Chemical energy to thermal(heat) energy
Explanation:
A gas burner contains chemical hydrocarbon such as methane, this methane is highly flammable.
The gas burner which contains methane when lighted up converts the chemical energy in the chemical to heat energy through the fire it produces. The fire then helps in heating up the surface it is applied to.
No, you can't see the equator.
Answer:
Explanation:
a ) If the image of this object is viewed with the eyepiece adjusted for minimum eyestrain (image at the far point of the eye) , the image from object lens must have been formed at the focus of eye lens . So the objective image must have been formed at 19.5 - 2.75 = 16.75 cm from the object lens.
b ) Let the object distance be u
For object lens
v = 16.75 cm , f = .35 cm
1/v - 1/u = 1/f
1/16.75 - 1/u = 1/ .35
.0597 - 1/u = 2.857
1/u = - 2.7973
u = .3575 cm
c ) Angular magnification
= 
v₀ and u₀ are image and object distance for object lens , D = 25 cm and f_e is focal length of eye lens
= (16.75 / .3575) x( 25 / 2.75)
= 46.85 x 9.09
= 426
