Answer:
Friction opposes motion.
Explanation:
If there is relative motion, the frictional force is the kinetic force of friction.
<span>They occur when the Earth, the Sun, and the Moon are in a line. </span>
Answer:
(a) 1.2 rad/s
(b) 1.8 rad
Explanation:
Applying,
(a) α = (ω-ω')/t................ Equation 1
Where α = angular acceleration, ω = final angular velocity, ω' = initial angular velocity, t = time.
From the question,
Given: α = 0.40 rad/s², t = 3 seconds, ω' = 0 rad/s (from rest)
Substitute these values into equation 1
0.40 = (ω-0)/3
ω = 0.4×3
ω = 1.2 rad/s
(b) Using,
∅ = ω't+αt²/2.................. Equation 2
Where ∅ = angle turned.
Substitutting the values above into equation 2
∅ = (0×3)+(0.4×3²)/2
∅ = 1.8 rad.
Answer:
a)The sign of energy is negative, b) we can approach the two charges, c) d ⇒ 0
Explanation:
a) The elective potential energy is
U = k q₁q₂ / r
Applied to this case.
U = -k q 9 / d
U = -9 k q / d
The sign of energy is negative, which corresponds to a stable system
b) c) for the energy to be more negative we can approach the two charges
c) To increase the energetic of the system, that is to say less negative, we can separate the discharges whereby U approaches zero or we can decrease the value of the charge q.
d ⇒ 0
