Answer:
1) 100 ...unb. and accelerate
2) 7...unb. and accelerate
Answer:
Explanation:
Moment of inertia of wheel = 1/2 x mR² , m is mass and R is radius of wheel
= .5 x 9 x .4²
= .72 kg m²
Torque created on wheel by string = T x r , T is tension and r is radius of wheel .
13 x .4 = 5.2 N m
angular acceleration α = torque / moment of inertia
= 5.2 / .72
= 7.222 rad /s²
a ) final angular speed = α x t , α is angular acceleration , t is time.
= 7.222 x .72
= 5.2 rad /s
b )
θ = 1/2 α t² , θ is angle turned , t is time
= .5 x 7.222 x .72²
= 1.872 rad
average angular speed = θ / t
= 1.872 / .72
= 2.6 rad /s
c )
angle turned = 1.872 rad ( discussed above )
d )
length of string coming off
= angle rotated x radius of wheel
= 1.872 x .4
= .7488 m .
74.88 cm
Answer:
(a)
(b) The force is repulsive
Explanation:
a) According to Coulomb's law, the magnitude of the electrice force that one particle exerts on the other is defined as:
Here k is the coulomb constant, and are the signed magnitudes of the charges and d is the distance between them.
b) According to Coulomb's law, if the two charges have the same sign, the electrostatic force between them is repulsive.
Sodium becomes positively charged because it has lost an electron