Francium-223 has a half-life of 22 minutes. A Geiger counter gives a reading of 58 counts per minute (cpm) from a sample of fran
1 answer:
Answer:
29 counts per minute (29 cpm)
Explanation:
The half-life of a radioactive isotope is the time needed for the activity of the sample to halve.The half-life of Francium-223 is exactly 22 minutes: this means that its activity after 22 minutes becomes exactly half of its initial value. Since the initial activity of this sample of francium-223 was 58 cpm, the activity after 22 minutes will be
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Answer:
1) 64.2 mi/h
2) 3.31 seconds
3) 47.5 m
4) 5.26 seconds
Explanation:
t = Time taken = 2.5 s
u = Initial velocity = 0 m/s
v = Final velocity = 21.7 m/s
s = Displacement
a = Acceleration
1) Top speed = 28.7 m/s
1 mile = 1609.344 m
1 hour = 60×60 seconds
Top speed of the cheetah is 64.2 mi/h
Equation of motion
Acceleration of the cheetah is 8.68 m/s²
2)
It takes a cheetah 3.31 seconds to reach its top speed.
3)
It travels 47.5 m in that time
4) When s = 120 m
The time it takes the cheetah to reach a rabbit is 120 m is 5.26 seconds
Answer: The magnitude of the current in the second wire 2.67A
Explanation:
Here is the complete question:
Two straight parallel wires are separated by 7.0 cm. There is a 2.0-A current flowing in the first wire. If the magnetic field strength is found to be zero between the two wires at a distance of 3.0 cm from the first wire, what is the magnitude of the current in the second wire?
Explanation: Please see the attachments below
Answer:
1.907 x 10⁻⁵ J.
Explanation:
Given,
Volume of space, V = 5.20 m³
Assuming the intensity of sunlight(S) be equal to 1.1 x 10³ W/m².
Electromagnetic energy = ?
where c is the speed of light.
Hence, Electromagnetic energy is equal to 1.907 x 10⁻⁵ J.
Answer:
As 28m/s = 28m/s
Explanation:
r = the radius of the curve
m = the mass of the car
μ = the coefficient of kinetic friction
N = normal reaction
When rounding the curve, the centripetal acceleration is
therefore
As 28m/s = 28m/s