Answer:
A 1.0 min
Explanation:
The half-life of a radioisotope is defined as the time it takes for the mass of the isotope to halve compared to the initial value.
From the graph in the problem, we see that the initial mass of the isotope at time t=0 is
The half-life of the isotope is the time it takes for half the mass of the sample to decay, so it is the time t at which the mass will be halved:
We see that this occurs at t = 1.0 min, so the half-life of the isotope is exactly 1.0 min.
D is the point where the planet moves the fastest. This is because it is in the perihelion, where the planet is moving at it’s fastest pace
Answer:
Powerful electromagnets are fitted on top of guideways either ttract or repel the magents fitted on the bottom of train. The froce of attraction/repulsion rasies the train in hovering position.
Explanation:
Magentic fields exist between two opposite/like poles. The poles do not have to be touching each other. They can be separated by a distance in a medium that doesn' block magnetic field.
In magelv train the magnetic forces between two poles are used to operate the train. The two poles are separated by train body and air.
Explanation:
Polaris also called North star is the brightest star in the the constellation Ursa Minor. It remains stationary whereas entire north sky move around it. It the point of north celestial pole.
A) False. This is because All of the stars move in a counterclockwise path around Polaris.
B) False. Reason stated above.
C) True, As the stars move towards the Polaris there orbital radius decreases as they move smaller circles.
D) False, As the stars move towards the Polaris there orbital radius decreases as they move smaller circles.
E) True.
F) False.
