Answer:
Systematic errors.
Explanation:
The density of the aluminium was calculated by a human and this is not natural but can be due to errors in the calibration of the scale for measuring the weight or taking readings from the measuring cylinder.
Random errors are natural errors. Random errors in experimental measurements are caused by unknown and unpredictable changes in the experiment. Systematic errors are due to imprecision or problems with instruments.
Answer:
The girl will move with constant velocity
Explanation:
If after a certain time t_0 the velocity of the girl is v_0 =gt_0 and the upward force on the girl due to rope is mg ,where g is gravitational acceleration. Then the girl will move down with the constant velocity v_0 .
The girl will move with constant velocity,as explained above.
First, J.J Thompson experimented with cathode ray tubes: sealed glass tubes at vaccum (without air inside), with two electrons (cathode and anode). When a high voltage was applied a beam of particles left from the cathode and passed throuhg two charged plates (one negative and one positive).
The beam of particles was deflected toward the positively-charged electric plate, which indeicatedd that the particles were negatively charged.
Given that Thompson experimented with different materials (cathode electrodes), that the results were always the same, and that the mass of the electrons were a small fraction (approximately 1/2000) of the hydrogen atom, he concluded that the negatively particle was part of the atom (a subatomic particle).
Also, given that the atom is neutral, he concluded that there were negative and positive particles in any atom, and he speculated that the negative particles (electrons) were scattered into the positive particles which were way more massive.
Answer:
In a permanent magnet, the magnetic field comes from the motion of the electrons inside the material, or, more precisely, from something called the electron spin. The electron spin is a bit like the Earth spinning on its axis. The magnetic field is a vector, the same way the electric field is.
Explanation:
