Answer:
Yes
Explanation:
Kinetic energy is K.E1/2mv2 so that means it is directly proportional to mass and velocity.
When a magnet is brought close to the picture tube, the interaction between the flying electrons and the magnetic field creates a force that throws the electrons off course. Now the electrons are hitting the screen in places they were not intended to strike and the picture becomes distorted.
When a television receives a signal, it first splits off the audio (sound) signal and the picture signal from a carrier wave (which is used to allow the signal to be transmitted over long distances). The audio is sent straight to the speakers to produce sound. The picture signal consists of three elements, red, green and blue. A standard television has three 'electron guns' at the back of the set, one for each colour. Let's start by looking at the red signal. The red signal is fed into one of these 'guns'. The gun produces a beam of electrons that varies in intensity with the strength of the red signal. This beam is fired towards the tv screen. The electron beam starts at the top-left of the screen and magnetic fields are used to 'sweep' this beam across the screen in parallel horizontal lines (if you look closely at a tv screen you can see these lines). UK televisions (PAL) have 625 lines and update the picture 25 times per second, US televisions (NTSC) have 525 lines but update 30 times per second. The back of the tv screen is covered in phosphor 'dots' (pixels) which glow when they are struck by these electrons. The red-signal electron beam is aimed so that it strikes phosphor dots that glow red, emitting photons which the eye can detect. The same process occurs for green and blue; each colour signal goes to one particular electron gun which excites just the dots of that colour, the signal tells the gun how strong it should be which in turn means some dots glow brighter than others. When you sit back from the tv screen, you don't notice the dots nor the flicker, your eye blends the image together to give a clear picture which appears to move. Now to answer the question! A magnet distorts the picture as it distorts the path of electrons flowing from the electron gun towards the screen inside the tv. As electrons are negatively charged particles, their motion is distorted by a magnet. So it is these electrons, not photons, which are distorted by the magnet. On older tvs, damage caused by holding a magnet too close to a tv could be permanent; newer tvs tend to have a demagnetisation process when you switch them on, to ensure that the picture is not permanently distorted. ehehe..
Answer:
a. negative
b. zero
Explanation:
work is the change in the energy of a system due to external forces
work is done when a force moves a load through a distance in the direction of the force
The work done by a force on a system is positive when the force and the force displacement point in the same direction and negative when they point in opposite directions
in the scenario we are considering in the question, the force (the hand) moves the block vertically upwards but the displacement of the block reduces (in the opposite direction) since it decelerates. as such the work done by gravity on the block is negative.
the work done on the block is zero if the system consists of the block and the earth because there is no gravitational force exerted on the system
B because willingness shows confidence in your answer
Answer:
The answer is -x direction.
Explanation:
According to the right hand rule for electromagnetism, when the thumb points up, index finger points forward and the middle finger is perpendicular to the index finger, the thumb points in the direction of the magnetic force, the index finger in the direction of the charge movement and the middle finger in the direction of the electromagnetic lines. If the electric field is pointing in the -z direction which is into the screen and the magnetic field is in the +y direction which is upwards, then the magnetic lines are in the -x direction.
I hope this answer helps.
