Answer:
t = 5.59x10⁴ y
Explanation:
To calculate the time for the ¹⁴C drops to 1.02 decays/h, we need to use the next equation:
(1)
<em>where
: is the number of decays with time, A₀: is the initial activity, λ: is the decay constant and t: is the time.</em>
To find A₀ we can use the following equation:
(2)
<em>where N₀: is the initial number of particles of ¹⁴C in the 1.03g of the trees carbon </em>
From equation (2), the N₀ of the ¹⁴C in the trees carbon can be calculated as follows:
<em>where
: is the tree's carbon mass,
: is the Avogadro's number and
: is the ¹²C mass. </em>
Similarly, from equation (2) λ is:
<em>where t 1/2: is the half-life of ¹⁴C= 5700 years </em>

So, the initial activity A₀ is:
Finally, we can calculate the time from equation (1):
I hope it helps you!
Answer:

Explanation:
Parameters given:
Charge of object, q = 5 mC = 
Acceleration of object, a = 
Mass of object, m = 2.0 g
The Electric field exerts a particular force on the object, causing it to accelerate (Electrostatic force).
We know that Electrostatic force, F, is given in terms of Electric field, E, as:
F = qE
This means that the object exerts a force of -qE on the Electric force (Action with equal and opposite reaction).
The object also has a force, F, due to its acceleration a. This force is the product of its mass and acceleration. Mathematically:
F = ma
Equating the two forces of the object, we get:
-qE = ma
=> 
Solving for E, we have:

The magnitude will be:

The electric field has a magnitude of 0.002 N/C.
The era that dinosaurs came was in the Mesozoic Era!
The period of the pendulum is 8.2 s
Explanation:
The period of a simple pendulum is given by the equation:

where
L is the length of the pendulum
g is the acceleration of gravity
T is the period
We notice that the period of a pendulum does not depend at all on its mass, but only on its length.
For the pendulum in this problem, we have
L = 16.8 m
and
(acceleration of gravity)
Therefore the period of this pendulum is

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Answer:
Acceleration of the meteorite, 
Explanation:
It is given that,
A Meteorite after striking struck a car, v = 0
Initial speed of the Meteorite, u = 130 m/s
Distance covered by Meteorite, s = 22 cm = 0.22 m
We need to find the magnitude of its deceleration. It can be calculated using the third equation of motion as :



So, the deceleration of the Meteorite is
. Hence, this is the required solution.