Answer:
29.38 seconds
Explanation:
Half life, T = 22.07 s
No = 1293
Let N be the number of atoms left after time t
N = 1293 - 779 = 514
By the use of law of radioactivity
Where, λ is the decay constant
λ = 0.6931 / T = 0.6931 / 22.07 = 0.0314 decay per second
so,
take natural log on both the sides
0.9225 = 0.0314 t
t = 29.38 seconds
Their common speed is 1.53 m/s.
<h3>What is speed?</h3>
Speed can be defined as the ratio of the distance to the time of a body in motion.
To calculate their final speed, we use the formula below.
Formula:
- mu+m'u' = V(m+m')............. Equation 1
Where:
- m = mass of the Lee
- m' = mass of Mat
- u = initial speed of Lee
- u' = initial speed of Mat
- V = Their common speed.
make V the subject of the equation
- V = (mu+m'u')/(m+m')........... Equation 2
From the question,
Given:
- m = 40 kg
- m' = 80 kg
- u = 4.6 m/s
- u' = 0 m/s
Substitute these values into equation 2
- V = [(40×4.6)+(80×0)]/(40+80)
- V = 184/120
- V = 1.53 m/s.
Hence, Their common speed is 1.53 m/s.
Learn more about speed here: brainly.com/question/3004254
The gravitational attraction between two planets is 4905.95 N
<h3>What is gravitational attraction?</h3>
When two objects with masses are placed at a distance, there will an attractive force acting between them.
According to the Newton's law of gravitation, gravitational force is
F = Gm₁m₂ /r²
where r is the distance between the masses m₁ and m₂ and G is the gravitational constant G = 6.67 x 10⁻¹¹ N-m²/kg²
Substitute the values into the expression, we get
F = 6.67 x 10⁻¹¹ x 2.25 x 10²⁰ x 6.20 x 10¹⁸ / (435,500 x 1000)²
F= 4905.95 N
Thus, the gravitational attraction between two planets is 4905.95 N.
Learn more about gravitational attraction.
brainly.com/question/19822389
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The weight of an object is the
force with which it is attracted to earth. The gravity of an object or body of
an object is high on earth than at the atmosphere. It has an average of
gravitational constant equal to 9.8066 or 9.8 meters per second. In truth, the acceleration
of the object depend upon its location, the latitude and altitude, on
earth.
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