Special relativity led the path for general relativity; special relativity is in a sense a special application of the rules of general relativity. While general relativity is in position to tackle all of these problems, special relativity can tackle only problems in inertial frames. Inertial frame means that the frame of reference is inot accelerating. So, we disqualify answers A and D. However, remember that moving in a circle means that there is an acceleration, the centrifugal one, even if the speed does not change. Hence C is also incorrect.
The correct answer is B, since if there is no change in velocity, the frame does not accelerate and it is inertial.
The time taken by the swimmer was 1 hour.
Why?
Since the swimmer is maintaining an angle of 150° while he was swimming, there were two components of the speed (horizontal and vertical). If we want to calculate the time taken by him to cross the river, we need to calculate the vertical speed and consider that the flow's speed is compensated by his horizontal speed.
We can calculate both components of the speed using the following formula:

Now, calculating we have:

Therefore, we have that the horizontal speed is compesating the flow's speed while his vertical speed is used to cross the river which is 1 Km wide.
Hence, we have that the tame taken is:

Have a nice day!
An atomic mass unit (symbolized AMU or amu) is defined as precisely 1/12 the mass of an atom of carbon-12. The carbon-12 (C-12) atom has six protons and six neutrons in its nucleus.
Answer:
I don't know what you're asking, but I will try my best.
If Susan fertilizes her geranium plants, it will help them blossom. If she over-fertilizes them though, they will die. But yes, in general, they will blossom if Susan fertilizes her geranium plants.
The acceleration of the car is
upward
Explanation:
We can solve the question by using Newton's Second Law of motion, which states that:

where
F is the net force exerted on an object
m is the mass of the object
a is its acceleration
In this problem, we know that:
F = 900 N is the net force exerted on the car
m = 750 kg is the mass of the car
Solving the equation for a, we find the acceleration of the car:

and it is in the same direction as the force (upward).
Learn more about Newton's second law of motion here:
brainly.com/question/3820012
#LearnwithBrainly