A bar on a hinge starts from rest and rotates with an angular acceleration α = 15+4t, where α is in rad/s2 and t is in seconds. Determine the angle in degrees through which the bar turns in the first 2.00 min.

230.53°

Explanation:

α = angle in rad / t^2

t =2mins = 2 × 60 = 120sec.

α = angle in rad / 2^2

α = angle in rad / 16

15+4(2) = angle in rad /4

23 = angle/4

23× 4 = angle in radian

92 = angle in radian

But π rad = 180°

1 rad = 180 /π

Therefore

92 rad = 92 ×180/π = 5270.53°

This value is far more so we subtract from 360° continuously till we get a value less than 360°

5270.53- (360×14) =5270.53- 5040

230.53°

an ion is a charged atom or molecule. it is charged because the number of electrons do not equal the number of protons in the atom or molecule. an atom can acquire a positive charge or a negative charge depending on whether the number of electrons in an atom is greater or less then the number of protons in the atom.