Consider an acrylic sheet of thickness L = 5 mm that is used to coat a hot, isothermal metal substrate at Th = 300°C. The proper
ties of the acrylic are rho = 1990 kg/m3, c = 1470 J/kg · K, and k = 0.21 W/m · K. Neglecting the thermal contact resistance between the acrylic and the metal substrate, determine how long it will take for the insulated back side of the acrylic to reach its softening temperature, Tsoft = 90°C. The initial acrylic temperature is Ti = 20°C.
1 answer:
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Answer:
Explanation:
Mass of the ship (m) = 6.9 × 10⁷ kg
Speed of the ship (v) = 33 km/h
First, let us convert the speed from km/h to m/s using the conversion factor.
We know that, 1 km/h = 5/18 m/s
So, 33 km/h =
Now, we know, the momentum of an object only depends on its mass and speed. Momentum is independent of the length of the object.
So, here, length of the ship doesn't play any role in the determination of the momentum.
Magnitude of momentum of the ship = Mass × Speed
=
=
Therefore, the magnitude of ship's momentum is .
Answer:
please read the answer below
Explanation:
The angular momentum is given by
By taking into account the angles between the vectors r and v in each case we obtain:
a)
v=(2,0)
r=(0,1)
angle = 90°
b)
r=(0,-1)
angle = 90°
c)
r=(1,0)
angle = 0°
r and v are parallel
L = 0kgm/s
d)
r=(-1,0)
angle = 180°
r and v are parallel
L = 0kgm/s
e)
r=(1,1)
angle = 45°
f)
r=(-1,1)
angle = 45°
the same as e):
L = 5kgm/s
g)
r=(-1,-1)
angle = 135°
h)
r=(1,-1)
angle = 135°
the same as g):
L = 5kgm/s
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