Two factors determine whether a substance is a solid, a liquid, or a gas: The kinetic energies of the particles (atoms, molecules, or ions) that make up a substance. Kinetic energy tends to keep the particles moving apart. The attractive intermolecular forces between particles that tend to draw the particles together.
A circle has a revolution of 360°. Since there are 12 hour markings, each hour interval has an angle of 30°. In radians, that would be equal to π/6 radians. So, in every 1 hour that passes, it covers π/6 of an angle. So, the angular velocity denoted as ω is π/6 ÷ 1 hour = π/6 rad/h. We can compute the average linear velocity, v, from the relationship:
v = rω, where r is the radius of the circle which is the length of the hour hand
v = (2.4 cm)(π/6 rad/h)
v = 1.257 cm/hour
Therefore, the average velocity is 1.257 cm per hour.
For the average acceleration, it is equal to zero. The hands of the clock move at a constant velocity. Since acceleration is the change of velocity per unit time, there is no change of velocity because it's constant. That's why it is zero.
Answer:
48.4 km, 34.3° north of east
Explanation:
Let's say east is the +x direction and north is the +y direction.
Adding up the x components of the vectors:
x = 20 cos 60 + 30 + 0
x = 40 km
Adding up the y components of the vectors:
y = 20 sin 60 + 0 + 10
y = 27.3 km
The magnitude of the displacement is:
d = √(x² + y²)
d = 48.4 km
The direction is:
θ = atan(y/x)
θ = 34.3° north of east
Answer:
a) 6.4 kJ
b) 43.4 kJ
Explanation:
a)
= Heat absorbed = 37 kJ
= Coefficient of performance = 5.8
= Work done
Heat absorbed is given as
=
37 = (5.8)
= 6.4 kJ
b)
= work per cycle required
= +
= 37 + 6.4
= 43.4 kJ
