practice questions Flashcards
what is zero error
Any indication that a measuring system gives a false reading when the true value of a measured quantity is zero
if batteries are inserted incorrect why dont they work
To get the voltage needed from multiple batteries, you need to put them in series. That is, you need the + from one battery connected to the - from the next battery, and so on.
why are gas power stations better than coal power stations
gas stations have 50 to 60 percent less greenhouse gas emmissions than carbon
gas power stations are much more reliable
what is a manmade cause of background radiation
x rays
one example of nuclear fuel
plutonium
what is nuclear fission
Nuclear fission is the splitting of a large atomic nucleus into smaller nuclei. In a nuclear reactor , a neutron is absorbed into a nucleus (typically uranium-235). This causes the nucleus to become uranium-236, which is violently unstable. The entire nucleus splits into two large fragments called ‘daughter nuclei ‘.
how does nuclear fission release energy
Fission is the splitting of heavy nuclei (such as uranium) – in two smaller nuclei. This process needs less energy to ‘bind’ them together – so energy is released.
what is an advantage of waste having a short halflife
If an isotope has a short half-life, it will decay quickly, and emit more particles in a given time than an isotope with a longer half-life. So isotopes with shorter half-lives have higher activity than those with longer half-lives.
6.3 explain terminal velocity
at the start, the object accelerates downwards due to the force of gravity
as the object’s speed increases, frictional forces such as air resistance or drag increase
at terminal velocity, the weight of the object due to gravity is balanced by the frictional forces, and the resultant force is zero
if more resistors are in a circuit why would the resistance be lower
In a parallel circuit, the net resistance decreases as more components are added, because there are more paths for the current to pass through.
