Amuseum curator moves artifacts into place on many different display surfaces. consider the following table giving approximate values for coefficients of friction: – schomer – (hhsphy4f18) 1 materials μs μk steel on steel 0.74 0.57 aluminum on steel 0.61 0.47 rubber on dry concrete 1.0 0.8 rubber on wet concrete – 0.5 wood on wood 0.4 0.2 glass on glass 0.9 0.4 waxed wood on wet snow 0.14 0.1 waxed wood on dry snow – 0.04 metal on metal (lubricated) 0.15 0.06 ice on ice 0.1 0.03 teflon on teflon 0.04 0.04 synovial joints in humans 0.01 0.003 what is fs, max for moving a 167 kg alu- minum sculpture across a horizontal steel platform? the acceleration of gravity is 9.81 m/s2 . answer in units of n.

you must give a force for just moving  

Fmax=151*0,61*9,81= 904 N <  

and  

F=151*0.47*9.81= 646 N ... to keep in motion

hope this helps :)

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.