Answer:
F₁ = 4 F₀
Explanation:
The force applied on the string by the ball attached to it, while in circular motion will be equal to the centripetal force. Therefore, at time t₀, the force on ball F₀ is given as:
F₀ = mv₀²/r --------------- equation (1)
where,
F₀ = Force on string at t₀
m = mass of ball
v₀ = speed of ball at t₀
r = radius of circular path
Now, at time t₁:
v₁ = 2v₀
F₁ = mv₁²/r
F₁ = m(2v₀)²/r
F₁ = 4 mv₀²/r
using equation (1):
<u>F₁ = 4 F₀</u>
We know that the source of light in the universe is the Sun. Hence, the light we see as moonlight travels from the Sun's surface, to the moon, then to Earth. So, before being able to solve this problem, we have to know the distance between the Sun and the moon, and the distance between the moon and Earth. In literature, these values are 3.8×10⁵ km (Sun to moon) and 384,400 km (moon to Earth). Knowing that the speed of light is 300,000 km per second, then the total time would be
Time = distance/speed
Time = (3.8×10⁵ km + 384,400 km)/300,000 km/s
Time = 2.548 seconds
Thus, it only takes 2.548 for the light from the Sun to reach to the Earth as perceived to be what we call moonlight.
False. this is just a physical change, not a chemical change.
They can be described as small in quantity and very dangerously radioactive.