In order to operate the theremin, a conducting object must be moved within the electric fields produced by the instrument
True ( I think ) ............................
0.8611 g/cm ^2
Density = mass/ volume
Kinetic energy:
1) A car traveling down the road has less kinetic energy than a semi-truck and traveling at the same speed because the car's mass is much less than the truck's.
2) A river flowing at a certain speed possesses kinetic energy because the water has a certain mass and it also has velocity.
3) An insect flying has a small amount of kinetic energy because its mass and velocity are relatively small.
Potential Energy:
1) The food we eat has chemical potential energy because as our body digests it, it provides us with energy for basic metabolism.
2) A stretched spring in a pinball machine has elastic potential energy and can move the steel ball when released.
3) When a crane swings a wrecking ball up to a certain height, it gains more potential energy and has the ability to crash through buildings.
Answer:
31.92 h
Explanation:
We'll begin by calculating the number of half-lives that has elapsed. This can be obtained as follow:
Original amount (N₀) = 1
Amount remaining (N) = ⅛
Number of half-lives (n) =?
N = 1/2ⁿ × N₀
⅛ = 1/2ⁿ × 1
Cross multiply
2ⁿ = 8
Express 8 in index form with 2 as the base.
2ⁿ = 2³
n = 3
Thus, 3 half-lives has elapsed.
Finally, we shall determine the time. This can be obtained as follow:
Half-life (t½) = 10.64 h
Number of half-lives (n) = 3
Time (t) =?
n = t / t½
3 = t / 10.64
Cross multiply
t = 3 × 10.64
t = 31.92 h
Therefore, it will take 31.92 h for lead-212 to decay to one-eighth its original strength.