Answer:
medium
Examples:
A medium is a thing that the sound wave would travel through, like sound waves traveling through air. A mechanical wave cannot travel without a medium, like if the wave were trying to travel through a vacuum.
"Three short blasts" sound signal alerts others when a boat is backing up based on the boating safety rule. The short blast is a sound which has one second period, thus three short blasts mean three of this kind of sound. The sound signal is used for alerting anything surrounding the boat to avoid a collision.
Answer:
3.036×10⁻¹⁰ N
Explanation:
From newton's law of universal gravitation,
F = Gm1m2/r² .............................. Equation 1
Where F = Gravitational force between the balls, m1 = mass of the first ball, m2 = mass of the second ball, r = distance between their centers.
G = gravitational constant
Given: m1 = 7.9 kg, m2 = 6.1 kg, r = 2.0 m, G = 6.67×10⁻¹¹ Nm²/C²
Substituting into equation 1
F = 6.67×10⁻¹¹×7.9×6.1/2²
F = 321.427×10⁻¹¹/4
F = 30.36×10⁻¹¹
F = 3.036×10⁻¹⁰ N
Hence the force between the balls = 3.036×10⁻¹⁰ N
Answer:
c)
Explanation:
As we know that resultant force is the net force that is acting on the system
As per Newton's II law we know that net force is product of mass and acceleration
so we will have

here we know
m = 80 kg
for circular motion acceleration is given as


now we have



The answer is 60 km. I hope it helps i dont know if this is right or wrong.