Answer:
Mirages happen when the ground is very hot and the air is cool.
Explanation:
They happen when light passes through two layers of air with different temperatures. The desert sun heats the sand, which in turn heats the air just above it. The hot air bends light rays and reflects the sky.
When you see it from a distance, the different air masses colliding with each other act as a mirror.
C. A mechanical wave generally travels faster in gases than liquids.
Answer:
The answer to your question is m₂ = 38.5 kg
Explanation:
Data
distance = d = 2.1 x 10⁻¹ m
Force = 3.2 x 10⁻⁶ N
m₁ = 55 kg
m₂ = ?
G = 6.67 x 10 ⁻¹¹ Nm²/kg²
Process
1.- To solve this problem use Newton's law of Universal Gravitation.
F = G m₁m₂ / r²
-Solve for m₂
m₂ = Fr² / Gm₁
2.- Substitution
m₂ = (3.2 x 10⁻⁶)(2.1 x 10⁻¹)² / (6.67 x 10⁻¹¹)(55)
3.- Simplification
m₂ = 1.411 x 10⁻⁷ / 3.669 x 10⁻⁹
4.- Result
m₂ = 38.5 kg
The last one is correct (D)
Answer:
True.
Explanation:
If the sum of the external forces on an object is zero, then the sum of the external torques on it must also be zero.
The net external force and the net external torque acting on the object have to be zero for an object to be in mechanical equilibrium.
Hence, the given statement is true.
