The formula for half-life is:
Where A is the amount of iodine-131 initially and after 40 days, t is time, h is half-life of the isotope. Let's plug in our values to the equation:
Therefore, the patient has 0.625 grams of iodine-131 after 40 days.
An object starts at rest. Its acceleration over 30 seconds is shown in the graph below:
1 answer:
Answer:
The instantaneous speed of the object after the first five seconds is 12.5 m/s.
(C) is correct option.
Explanation:
Given that,
An object starts at rest. Its acceleration over 30 seconds.
We need to calculate the instantaneous speed of the object after the first five seconds
We know that,
Area under the acceleration -time graph gives speed.
According to figure,
Hence, The instantaneous speed of the object after the first five seconds is 12.5 m/s.
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Answer:
The weight of the landing craft in the vicinity of Callisto's surface is 3480 N.
Explanation:
The engine of the craft provides an upward thrust of so that the space craft descends at a constant speed.
This implies that the net force on the space craft is zero.
The upward thrust will be equal to the downward gravitational pull by Callisto.
So the weight of the craft near the vicinity will be 3480 N.
<h2>QUESTION:- </h2>
➜what is kepler's law??
Kepler gave the three laws or theorems of motion of the orbitals bodies
This law state that the celestial bodies revolves around the stars in elliptical orbit and star as a single focus.
Example :- Earth revolves around the Sun as assuming it as single focus
This also shows that earth revolves around the sun in elliptical orbit.
Area covered by the planet is equal in equal duration of time irrespective of the position of the planet.
It also states that Angular momentum is constant
As Angular momentum is constant it means areal velocity is also constant.
where:-
A is the area.
T is the time.
L is the angular momentum.
M is the mass of the body.
square of the time of the revolution is directly proportional to the cube of the distance between the planet and star in Astronomical unit.
where:-
T = time of revolution
a is the distance between the planet and star.