The chair does not move along the vertical direction: this means that the net force on the vertical direction is zero.
There are three forces acting along the vertical direction:
- The weight, acting downward: 
- The component of the force F perpendicular to the floor, acting downward: 
- The normal force N, acting upwards.
Since the net force must be zero, we have:

From which we can find the value of N:

Answer:
either +z direction or -z direction.
Explanation:
The direction of the electric field, in an electromagnetic wave always is perpendicular to the direction of the magnetic field and the direction of propagation of the wave.
You assume a system of coordinates with the negative x axis as the west direction, and the y axis as the up direction
In this case, the wave is propagating toward the west (- x direction), and the magnetic field vector points up (+ y direction), then, it is mandatory that the electric field vector points either +z direction or -z direction.
Joule
The standard unit for kinetic energy is the joule (J). The joule is the standard unit for energy in general. Other units for energy include the newton-meter (Nm) and the kilogram meter squared over seconds squared (kg m2/s2).
Answer:
1) Some light waves bounce off the inner part of the film.
2) In doing so they travel a bit than the waves bouncing off the outer waves.
so we see colors repeat in pattern in a thin soap film
Explanation:
A colorful interference pattern is observed when light is reflected from the top and bottom boundaries of a thin oil film. The different bands form as the film's thickness diminishes from a central runoff-point.
When white light shines on a bubble, strange things happen. When light waves hit a bubble, some of them bounce straight back off the outer part of the soap film. Others carry on through but then bounce off the inner part of the film. So one set of light rays shine into a soap bubble, but two sets of rays come back out again. When they emerge, the waves that bounce off the inner film have traveled a tiny bit further than the waves that bounced off the outer film. So we have two sets of light waves that are now slightly out of step. Like two sets of ripples on a pond, these waves start merging. Just like on a pond, some add together and some cancel out. The overall effect is that some of the colors in the original white light disappear altogether, leaving other colors behind. These are the colors you see in soap bubbles.
Answer:
Sharper images will be produced by the new telescopes.
Construction and maintenance is expensive
Explanation:
The telescopes are put in space so that unfiltered light is received by the telescope. Telescopes on Earth receive light after the light has passed through our atmosphere. This affects the final image of the telescope.
Some of the telescopes being planned in the future are the Extremely Large Telescope (ELT) with mirror aperture diameter of 39.3 m, Thirty Meter Telescope (TMT) with mirror aperture diameter of 30 m, Giant Magellan Telescope (GMT) with mirror aperture diameter of 24.5 m. These mirrors have a significantly larger mirror aperture diameter than the space telescopes. The ELT will be able to produce an image 16 times sharper than the Hubble Telescope. It is also very expensive to make an maintain a telescope in space.
Keeping all this in mind the new telescopes are being made on Earth.