Answer:
Option B. 32 g
Explanation:
From the question given above, the following data were obtained:
Original amount (N₀) = 128 g
Half-life (t½) = 2.25 billion years
Number of half-lives (n) = 2
Amount remaining (N) =?
The amount of 128 gram of Radium-226 that will remain after 2 half-lives has elapsed can be obtained as followb
N = 1/2ⁿ × N₀
N = 1/2² × 128
N = 1/4 × 128
N = 0.25 × 128
N = 32 g
Therefore, 32g of the sample will remain.
<span>They are balanced. If the forces were not balanced the book would move*. In this example, the downward force of gravity on the book is counterbalanced by the upthrust of the desk. </span>
Answer:

Explanation:
Given:
- average walking speed,

- average biking speed,

<u>According to given condition:</u>

where:
time taken to reach the building by walking
time taken to reach the building by biking
We know that,

so,



<span>(c) energy travels from the object at higher temperature
to the object at lower temperature.
Size and mass have no effect.</span>
Answer:
E=
Explanation:
We are given that
Charge on ring= Q
Radius of ring=a
We have to find the magnitude of electric filed on the axis at distance a from the ring's center.
We know that the electric field at distance x from the center of ring of radius R is given by

Substitute x=a and R=a
Then, we get




Where K=
Hence, the magnitude of the electric filed due to charged ring on the axis of ring at distance a from the ring's center=