Answer:
B. positive; negative.
Explanation:
From the viewpoint of Principle of Energy Conservation and Work-Energy Theorem, we notice that gravity represents a conservative force, associated with gravitational potential energy, whereas air resistance is a non-conservative force, associated with dissipated work. Therefore, the work done by gravity is positive and work done by air resistance is negative. Therefore, the correct answer is B.
Answer:
C
Explanation:
As water vapor rises, it cools. Then drops get closer and over time will form clouds.
Force = mass x acceleration
force = 2500kg x (20m/s / 10m/s)
force = 2500kg x 2m/s^2
force = 5000kg m/s^2 = 5kN
i hope this is right (^^)
Answer: Amplitude
Explanation: The intensity or loudness of a sound depends upon the extent to which the sounding body vibrates (i.e the amplitude of vibration).
Loudness is measured in units called decibels and amplitude in metre
Answer:
The force needed will be greater to hold the object at rest.
Explanation:
For a better understanding let's take a look at the attached image.
In the image there is an example of this condition, we have an object of 3 kg-f mass, the first angle between the horizontal and the inclined plane is 35°. When we increase the angle to 45°. We can realize that we need to hold the object with a stronger force.
The calculation and the equations based on Newton's laws can be found in the attached image.