Answer:
Different surfaces
<h3>You can see that dull surfaces are good absorbers and emitters of infrared radiation. Shiny surfaces are poor absorbers and emitters (but they are good reflectors of infrared radiation</h3>
The answer is D using the work formula
W= F•d but if it was against gravity, it would be 0 if gravity is exerting the same amount, I would pick D using the formula, but I'm not so sure sorry
Answer:
1)
2)
3)
4)
Explanation:
1)
We can use the following equation:

Here, the initial velocity in the y-direction is zero, the final y position is zero and the initial y position is 25 m.


2)
The equation of the motion in the x-direction is:



3)
The velocity in the y-direction of the stone will be:



Now, the velocity in the x-direction is 15 m/s then the velocity will be:

4)
The angle of this velocity is:
Then α=55.92° negative from the x-direction.
I hope it helps you!
Answer:
4.96×10¯¹⁰ N
Explanation:
The following data were obtained from the question:
Mass 1 (M1) = 300 Kg
Mass 2 (M2) = 300 Kg
Separating distance (r) = 110 m
Gravitational constant (G) = 6.67×10¯¹¹ Nm²/Kg²
Gravitational force (F) =?
The gravitational force between the two goal posts can be obtained as follow:
F = GM1M2 / r²
F = 6.67×10¯¹¹ × 300 × 300 / 110²
F = 6.003×10¯⁶ / 12100
F = 4.96×10¯¹⁰ N
Therefore the gravitational force between the two goal posts is 4.96×10¯¹⁰ N
Explanation:
It is given that,
Frequency of diagnostic ultrasound, f = 3.82 MHz = 3820 Hz
The speed of the sound in air, v = 343 m/s
(a) We need to find the wavelength in air of such a sound wave. Let it is given by λ₁
i.e. 


(b) If the speed of sound in tissue is 1650 m/s .



Hence, this is the required solution.