Answer:
a. Big Bang Theory explains the beginning of the universe. The entire matter of the universe is believed to be concentrated in a single point. This point had infinite density. At time, t = 0, at the big bang, universe started expanding and cooling down. This theory is most widely accepted theory describing the beginning of the universe. It is not considered as hypothesis because of the evidences received by the scientists- detection of cosmic microwave background, red shift of the light received from the galaxies indicating that universe is expanding.
b. Cosmic Microwave background radiation is a faint radiation having average temperature of 3 K detected every where around from the sky. This is a residual radiation from 400,000 years after the beginning of the universe. The universe was very hot and dense at the beginning and thus, opaque. Hence, detection of the CMB has provided the evidence of Big bang theory.
c. Scientists have proposed three models of the universe:
1. closed universe- The universe has finite volume and curves around itself. The space-time has positive curvature.
2. open universe - The universe has infinite volume and has a negative curvature.
3. flat universe - The universe has zero curvature. It has infinite volume. The actual density of the universe is equal to the critical density of the universe. The expansion rate slows down over time. This is the most widely accepted model.
A coil of wire that is carrying a current and produces a magnetic field is called a solenoid. So the correct option is option "B", in regards to the question given. The term solenoid was first invented by the famous French physicist named Andre-Marie Ampere. In the terms of a physicist, it indicates a coil that has a far greater lenth than the diameter and is wrapped around a core made of metal to create a uniform magnetic field. If a compass is brought near the wire through which current is passing, it will indicate the direction in which the current is flowing.
D, as he is testing which type of fertiliser is the best, and hence it should be the only changed variable. Everything else should remain the same.
The answer is B. Just had it on usatestprep
Answer:
Suppose the micrometeoroid weighed 1 g = .001 kg
Suppose also the spacecraft were moving at 18,000 mph (1.5 hrs per rev)
Usually, the smaller particle would be moving but for simplicity suppose that it were stationary wrt the ground
v = 18000 miles / hr * 1500 m/mile / 3600 sec/hr = 7500 m/s
KE = 1/2 * .001 kg * (7500 m)^2 = 28,125 Joules
One can see that 28000 Joules could be damaging amount of energy