Density = (mass) / (volume)
Density = (20 g) / (5 cm³)
<em>Density = 4 g/cm³</em> .
The density of the substance is greater than the density of water. A lump of the substance <em>will sink in water</em>, <u>unless</u> the lump is formed into a shape that displaces 20 cm³ of water or more, such as a tiny boat shape.
any two uses of good conductor of heat are
aluminium, cooper, metal are good conductor of heat and they are used for making utensils.
gold, silver, are also good conductor of heat they are used for making jewelleries.
The given question is incomplete. The complete question is as follows.
The block has a weight of 75 lb and rests on the floor for which
= 0.4. The motor draws in the cable at a constant rate of 6 ft/sft/s. Neglect the mass of the cable and pulleys.
Determine the output of the motor at the instant
.
Explanation:
We will consider that equilibrium condition in vertical direction is as follows.
![\sum F_{y} = 0](https://tex.z-dn.net/?f=%5Csum%20F_%7By%7D%20%3D%200)
N - W = 0
N = W
or, N = 75 lb
Again, equilibrium condition in the vertical direction is as follows.
![\sum F_{x} = 0](https://tex.z-dn.net/?f=%5Csum%20F_%7Bx%7D%20%3D%200)
= 0
![T_{2} = \mu_{k} N](https://tex.z-dn.net/?f=T_%7B2%7D%20%3D%20%5Cmu_%7Bk%7D%20N)
= ![0.4 \times 75 lb](https://tex.z-dn.net/?f=0.4%20%5Ctimes%2075%20lb)
= 30 lb
Now, the equilibrium equation in the horizontal direction is as follows.
![\sum F_{x} = 0](https://tex.z-dn.net/?f=%5Csum%20F_%7Bx%7D%20%3D%200)
![T Cos (30^{o}) + T Cos (30^{o}) = T_{2}](https://tex.z-dn.net/?f=T%20Cos%20%2830%5E%7Bo%7D%29%20%2B%20T%20Cos%20%2830%5E%7Bo%7D%29%20%3D%20T_%7B2%7D)
![2T Cos (30^{o}) = T_{2}](https://tex.z-dn.net/?f=2T%20Cos%20%2830%5E%7Bo%7D%29%20%3D%20T_%7B2%7D)
or, T = ![\frac{T_{2}}{2 Cos (30^{o})}](https://tex.z-dn.net/?f=%5Cfrac%7BT_%7B2%7D%7D%7B2%20Cos%20%2830%5E%7Bo%7D%29%7D)
= ![\frac{30}{2 Cos (30^{o})}](https://tex.z-dn.net/?f=%5Cfrac%7B30%7D%7B2%20Cos%20%2830%5E%7Bo%7D%29%7D)
= ![\frac{30}{1.732}](https://tex.z-dn.net/?f=%5Cfrac%7B30%7D%7B1.732%7D)
= 17.32 lb
Now, we will calculate the output power of the motor as follows.
P = Tv
= ![17.32 lb \times 6](https://tex.z-dn.net/?f=17.32%20lb%20%5Ctimes%206)
= ![103.92 \times \frac{1}{550} \times \frac{hp}{ft/s}](https://tex.z-dn.net/?f=103.92%20%5Ctimes%20%5Cfrac%7B1%7D%7B550%7D%20%5Ctimes%20%5Cfrac%7Bhp%7D%7Bft%2Fs%7D)
= 0.189 hp
or, = 0.2 hp
Thus, we can conclude that output of the given motor is 0.2 hp.
Explanation:
Momentum before = momentum after
m₁ u₁ + m₂ u₂ = m₁ v₁ + m₂ v₂
(50.0 kg) (0 m/s) + (12.0 kg) (0 m/s) = (50.0 kg) (2.0 m/s) + (12.0 kg) v
v = -8.33 m/s
Answer:
Not between significant digits.
Explanation:
A zero not significant when it's not between significant digits.