Answer:
Both conduction and convection need matter to transfer thermal energy.
Conduction involves collision of particles, while convection involves the movement of a liquid or gas.
Explanation:
There are three ways in which heat is transmitted:
1. By Conduction, when the transmission is by the direct contact (through collisions).
2. By Convection, heat transfer in fluids making a current created by less dense fluids floating and more dense fluids sinking (like water or the air, for example).
3. By Radiation, by the electromagnetic waves (they can travel through any medium and in vacumm)
Therefore, both conduction and convection need matter to transfer thermal energy (unlike radiation).
-- From the point of view of an observer on Earth, the moon's orbit is an ellipse
with the Earth's center at one focus.
-- From the point of view of an observer on the sun, or on any other planet,
the moon's orbit is an ellipse with the sun at one focus, and perturbed by being
near the Earth.
Answer:
(a) x=ASin(ωt+Ф₀)=±(√3)A/2
(b) x=±(√2)A/2
Explanation:
For part (a)
V=AωCos(ωt+Ф₀)⇒±0.5Aω=AωCos(ωt+Ф₀)
Cos(ωt+Ф₀)=±0.5⇒ωt+Ф₀=π/3,2π/3,4π/3,5π/3
x=ASin(ωt+Ф₀)=±(√3)A/2
For part(b)
U=0.5E and U+K=E→K=0.5E
E=K(Max)
(1/2)mv²=(0.5)(1/2)m(Vmax)²
V=±(√2)Vmax/2→ωt+Ф₀=π/4,3π/4,7π/4
x=±(√2)A/2
Answer:
28.1 mph
Explanation:
The force of friction acting on the car provides the centripetal force that keeps the car in circular motion around the curve, so we can write:
(1)
where
is the coefficient of friction
m is the mass of the car
g = 9.8 m/s^2 is the acceleration due to gravity
v is the maximum speed of the car
r is the radius of the trajectory
On the snowy day,
So the radius of the curve is
Now we can use this value and re-arrange again the eq. (1) to find the maximum speed of the car on a sunny day, when 
. We find:
