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3 years ago

A 20-kilogram box is sitting on an inclined plane with a 30-degree slope. If the box is at rest, what is the force

Physics

1 answer:

ad-work [718]3 years ago

7 0

Answer:

Explanation:

The box is at rest because , the component of weight along the surface downwards is equal to frictional force .

frictional force = mgsinθ

= 20 x 9.8 sin 30

= 98 N .

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If a bird flies from its nest to the ground and back are the distance and displacment the sam

Bezzdna [24]

No. They are different. The bird's distance for that period of time is double the height of the nest above the ground. His displacement for the same time is zero ... the length between the start point and end point.

8 0

3 years ago

A sharp edged orifice with a 60 mm diameter opening in the vertical side of a large tank discharges under a head of 6 m. If the

Ierofanga [76]

Answer:

The discharge rate is $Q = 0.0192 \ m^3 /s$

Explanation:

From the question we are told that

The diameter is $d = 60 \ mm = 0.06 \ m$

The head is $h = 6 \ m$

The coefficient of contraction is $Cc = 0.68$

The coefficient of velocity is $Cv = 0.92$

The radius is mathematically evaluated as

$r = \frac{d}{2}$

substituting values

$r = \frac{ 0.06 }{2}$

$r = 0.03 \ m$

The area is mathematically represented as

$A = \pi r^2$

substituting values

$A = 3.142 * (0.03)^2$

$A = 0.00283 \ m^2$

The discharge rate is mathematically represented as

$Q = Cv *Cc * A * \sqrt{ 2 * g * h}$

substituting values

$Q = 0.68 * 0.92* 0.00283 * \sqrt{ 2 * 9.8 * 6}$

$Q = 0.0192 \ m^3 /s$

6 0

2 years ago

A smith needs to melt 0.0500 kg of gold at 21.0°C. How much heat must be added? (Remember, she has to heat it to the melting poi

baherus [9]

Answer:

9704.6 J

Explanation:

Total Thermal Energy

= Energy required to bring gold to melting point + Energy required to change the state of gold from solid to liquid

= mcT + mlf [bolded is energy used to bring gold to melting point, italicised is state change of gold from sold to liquid]

= (0.0500)(126)(1063 - 21) + (0.0500)(6.28 × 10^4)

= 9704.6 J

4 0

3 years ago

A platinum ball weighing 100 g is removed from a furnace and dropped into 400 g of water at 0 degree C. If the equilibrium tempe

kakasveta [241]

Answer:

T = 1010 degree Celsius

Explanation:

mass of ball (Mb) = 100 g

mass of water (Mw) = 400 g

temp of water = 0 degree

specific heat of platinum (C) = 0.04 cal/g degree celsius

we can calculate the temperature of the furnace from the equation before

Mb x C x (temp of furnace (T) - equilibrium temp) = Mw x (equilibrium temp - temp of furnace)

100 x 0.04 x ( T - 10) = 400 x (10 - 0)

4 (T - 10) = 4000

T - 10 = 1000

T = 1010 degree Celsius

3 0

3 years ago

10. Almost three-quarters of household energy use is due to the following:

Arturiano [62]

Answer: Energy consumption and sustainability is important so that it remain available for future generation.

Explanation:

1. The home furnaces are likely to require fuel like coal, which will directly emit carbon dioxide and carbon monoxide gases. These should be replaced with the electrical furnaces. The old or more power consuming air conditioners should be replaced with new ones.

2. The water heaters should be tankless so their capacity to heat more water could be possible. The water heaters should be electricity saving.

3. Washer and dryers should be water savy and electricity savy. A front-loading washing machine is useful energy saver.

4. The LED lights are more electricity saving than conventional bulbs. Halogen lights are also electricity saving.

7 0

3 years ago