Answer:
Behaves as a wave.
Explanation:
The dual nature of light means that light behaves as a wave. If the light consisted of small particles, the alternating light and dark bands would not have occurred.
Sometimes it behaves like a particle (called a photon), which explains how light travels in straight lines.
Answer:
System D --> System C --> System A --> System B
Explanation:
The gravitational force between two masses m1, m2 separated by a distance r is given by:

where G is the gravitational constant. Let's apply this formula to each case now to calculate the relative force for each system:
System A has masses m and m separated by a distance r:

system B has masses m and 2m separated by a distance 2r:

system C has masses 2m and 3m separated by a distance 2r:

system D has masses 4m and 5m separated by a distance 3r:

Now, by looking at the 4 different forces, we can rank them from the greatest to the smallest force, and we find:
System D --> System C --> System A --> System B
The answer is 2500 newtons. F = M * A, so 500 kg x 5 m/s = 2500 newtons.
Answer:
140 beats per minute
Explanation:
You have to multiply the ratio 14 beats/6 seconds by 10 because 6 seconds times 10 to get 1 minute. The answer you get is 140 beats/60 seconds.