The correct answer is option (c) i.e. one
<span>The seat belt across your chest should have about one fist width of the slack. Because the seat belt across your chest is required to have minimum fist width of the slack to hold the body in place and to avoid slamming of the body against the seat belt in case of a collision at high speeds. To have one fist width of the slack, makes it a safest to wear it in case of any collision. </span>
Lighting a match
hope the answer helped!
Proton: symbol P, + 1
neutron: symbol n, 0
Electron: symbol e, -1
De Broglie's identity gives the relationship between the momentum and the wavelength of a particle:
where
p is the particle momentum
m is its mass
v its velocity
h is the Planck constant
is the wavelength
By re-arranging the equation, we get
and by using the data about the proton, given in the text, we can find the proton's wavelength: