In a convection current, as the temperature of a fluid increases, it's DENSITY decreases.
When a fluid is heated, it expands. With expansion, the density of the fluid decreases and the fluid starts to rise up. As the fluid rises up, it cools and so its density decreases and it starts to fall down.
This process repeats as long as the fluid is being heated. That's why we have a convection current.
Answer:
120,000 J
Explanation:
The work done by a force applied parallel to an object is given by:
where
F is the magnitude of the force applied
d is the displacement of the object
In this problem:
F = 8000 N is the force exerted by the elevator to lift the passenger
d = 15 m is the displacement of the elevator
Therefore, the work done in this situation is
So, the work done is 120,000 J.
The answer is the vehicle. At the precise moment of the impact in a collision, there is the release of energy when a vehicle strikes another vehicle or another object. Earlier to an impact, a vehicle and everything inside the vehicle is traveling at whatever speed the vehicle had been going. As the collision continues, the vehicle slowly loses energy. However, the vehicle occupants and any others items in the vehicle continue to move forward at the same speed as the vehicle had been traveling prior to impact.
Answer: choices a and b
Explanation:
Telescope can be defined as am optical instrument which is designed to observe the distant objects clear and nearer. It comprises of arrangement of lenses which allow the rays of light to be collected. The collected light is focused and the image so produced is magnified in the form of an image. The telescopes are prepared and manufactured on mountains top as this will help in preventing the distortion of light obtain from the star due to the fluctuation of air mass in the atmosphere. The atmospheric distortion affects the resolution, and affects the vision. The atmospheric pressure is low at the mountain tops so it will help in better observation of the sky.
The weight of an object is mass*acceleration. In this case mass*g.
1000*9.8=9800
So the car has a weight of 9800 N.