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Natali [406]
4 years ago
8

Una pregunta del significado de luminosity

Physics
1 answer:
NeX [460]4 years ago
3 0
Can you translate the question?
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The forklift exerts a 1,500.0 N force on the box and moves it 3.00 m forward to the stack. How much work does the forklift do ag
Deffense [45]
The answer is D using the work formula
W= F•d but if it was against gravity, it would be 0 if gravity is exerting the same amount, I would pick D using the formula, but I'm not so sure sorry
7 0
4 years ago
HELPPP
sergey [27]

Answer:

?

Explanation:

more explanationsplisss

4 0
3 years ago
A man wishes to row the shortest possible distance from north to south across a river which is flowing at 2 km/hr from the east.
sweet-ann [11.9K]

From the diagram we have that

sin\theta = \frac{2}{4}

\theta = sin^{-1} (\frac{1}{2})

\theta = 30\°

Therefore the direction is 30° from east of south

8 0
4 years ago
1. An object on Earth and the same object on the Moon would have a difference in
Feliz [49]

Answers: (1) a. weight, (2)b. Force changes by 2/9, (3)b. movement, (4)a. 40,000 Joules, (5)c. the soil will be 5°C.

<h2>Answer 1: a. weight</h2>

Mass and weight are very different concepts.  

Mass is the amount of matter that exists in a body, which only depends on the quantity and type of particles within it. This means mass is an intrinsic property of each body and remains the same regardless of where the body is located.  

On the other hand, weight is a measure of the gravitational force acting on an object and is directly proportional to the product of the mass m of the body by the acceleration of gravity g:  

W=m.g  

Then, since the Earth and the Moon have different values ​​of gravity, t<u>he weight of an object in each place will vary</u>, but its mass will not.

<h2>Answer 2: b. Force changes by 2/9</h2>

According to the law of universal gravitation, which is a classical physical law that describes the gravitational interaction between different bodies with mass:  

F=G\frac{m_{1}m_{2}}{r^2} (1)

Where:  

F is the module of the force exerted between both bodies  

G is the universal gravitation constant

m_{1} and m_{2} are the masses of both bodies.

r is the distance between both bodies

If we double the mass of one object (for example 2m_{1}) and triple the distance between both (for example 3r). The equation (1) will be rewritten as:

F=G\frac{2m_{1}m_{2}}{(3r)^2} (2)

F=\frac{2}{9}G\frac{m_{1}m_{2}}{r^2} (3)

If we compare (1) and (2) we will be able to see the force changes by 2/9.

<h2>Answer 3: b. movement</h2>

The Work W done by a Force F refers to the release of potential energy from a body that is <u>moved</u> by the application of that force to overcome a resistance along a path.  

When the applied force is constant and <u>the direction of the force and the direction of the movement are parallel,</u> the equation to calculate it is:  

W=(F)(d)

Now, <u>when they are not parallel, both directions form an angle</u>, let's call it \alpha. In that case the expression to calculate the Work is:  

W=Fdcos{\alpha}

Therefore, pushing on a rock accomplishes no work unless there is movement (independently of the fact that movement is parallel to the applied force or not).

<h2>Answer 4: a. 40,000 Joules</h2>

The Kinetic Energy is given by:

K=\frac{1}{2}mV^{2}   (4)

Where m is the mass of the body and V its velocity

For the first case (kinetic energy K_{1}=10000J  for a car at V_{1}=30 mph=13.4112m/s):

K_{1}=\frac{1}{2}mV_{1}^{2}   (5)

Finding m:

m=\frac{2K_{1}}{V_{1}^{2}}   (6)

m=\frac{2(10000J)}{(13.4112m/s)^{2}}   (7)

m=111.197kg   (8)

For the second case (unknown kinetic energy K_{2}  for a car with the same mass at V_{2}=60 mph=26.8224m/s):

K_{2}=\frac{1}{2}mV_{2}^{2}   (9)

K_{2}=\frac{1}{2}(111.197kg)(26.8224m/s)^{2}   (10)

K_{2}=40000J   (11)

<h2>Answer 5: c. the soil will be 5°C</h2>

The formula to calculate the amount of calories Q is:

Q=m. c. \Delta T   (12)

Where:

m  is the mass

c  is the specific heat of the element. For water is c_{w}=1 kcal/g\°C  and for soil is c_{s}=0.20 kcal/g\°C  

\Delta T  is the variation in temperature (the amount we want to find for both elements)

This means we have to clear \Delta T from (12) :

\Delta T=\frac{Q}{m.c}   (13)

For Water:

\Delta T_{w}=\frac{Q_{w}}{m_{w}.c_{w}}   (14)

\Delta T_{w}=\frac{1kcal}{(1kg)(1 kcal/g\°C)}   (15)

\Delta T_{w}=1\°C)}   (16)

For Soil:

\Delta T_{s}=\frac{Q_{s}}{m_{s.c_{s}}   (17)

\Delta T_{s}=\frac{1kcal}{(1kg)(0.20 kcal/g\°C)}   (18)

\Delta T_{s}=5\°C)}   (19)

Hence the correct option is c.

5 0
3 years ago
Read 2 more answers
A truck speed from rest to 120km/h in 13s. Find its acceleration. (convert to m/s)
ioda

answer:

2.5 m/s²

Explanation:

120 km/h = 120 ÷ 3.6 = 100/3 ≈ 33 m/s

a = (v2 - v1)/∆t = (33m/s - 0)/ 13s = 33/13 m/s²≈ 2.5 m/s²

4 0
3 years ago
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