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____ [38]
3 years ago
10

A 9 kg box is placed on a 6 m tall shelf. What will be the kinetic energy of the box right before it hits the ground? (use g = 1

0 m/s/s)
Physics
1 answer:
m_a_m_a [10]3 years ago
5 0

Answer:

540 J

Explanation:

U at top equals to K at bottom if it's an isolated system therefore U at top is equals to 540 J so we can assume that at 0m U=0 (mgh) therefore the box has gained some velocity due to the acceleration due to g and we can calculate it using 1/2mv²

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A physics major is cooking breakfast when he notices that the frictional force between the steel spatula and the Oiled Steel fry
Alinara [238K]

Answer:

N  = 6.67 N

Explanation:

The frictional or frictional force is a force that arises from the contact of two bodies and opposes movement.

The friction is due to imperfections and roughness, mainly microscopic, that exist on the surfaces of the bodies. Upon contact, these roughnesses engage with each other making movement difficult. To minimize the effect of friction, either the surfaces are polished or lubricated, since the oil fills the imperfections, preventing them from snagging.

As the frictional force depends on the materials and the force exerted on one another, its magnitude is obtained by the following expression:

f = μ*N    Formula (1)

where:  

f is the friction force  (N)

μ is the coefficient of friction

N is the normal force (N)

Data

f = 0.2 N : frictional force between the steel spatula and the Oiled Steel frying pan

μ = 0.03 :coefficient of kinetic friction between the two materials

Calculating of normal force

We replace data in the formula (1)

f = μ*N  

0.2  = 0.03*N  

N  = 0.2 / 0.03

N  = 6.67 N

5 0
3 years ago
Compare and contrast the general characteristics of a gas giant planet and one of the inner planets (such as Mercury, Earth, Ven
yKpoI14uk [10]
The gas planets usually have extremely high gravitational pulls, the surface isn't solid (since its a gas planet), and gas planets are larger than the inner planets. 
<span>Similarities- These planets all have moons and they both revolve around the sun (obviously).


Hope this helps.</span>
6 0
3 years ago
An engine has an energy input of 125j and 35 j of that energy is transformed into useful energy
Tatiana [17]
The engine's efficiency is (35J)/125J) = 28% .

Do you have a different question to ask ?
5 0
3 years ago
A crane is used to lower weights into a lake for an underwater construction project. Determine the tension in the cable of the c
atroni [7]

Answer:

Tension in the cable = 591292.8 N or 591.3 kN

Explanation:

Tension in the cable = Weight of object in air - upthrust/bouyancy due to the liquid

Weight of object in air = mass * acceleration due to gravity, g

Since mass is not given, it is obtained from the formula, mass = density * volume

Volume of the sphere = 4/3πr³ where r, radius = 2 m; π = 22/7

volume = 4/3 * 22/7 * (2m)³

volume of sphere = 33.52 m³

Density of concrete sphere = specific gravity * density of water

where, specific gravity = 2.8, density of water = 1000 kg/m³

density of concrete =  2.8 * 1000 kg/m³

density of concrete = 2800 kg/m³

acceleration due to gravity, g = 9.8 m/s²

Thus, weight of concrete = 2800 kg/m³ * 33.52 m³ * 9.8 m/s² = 919788.8 N

Upthrust = density of water * volume of sphere * g

Upthrust = 1000 kg/m³ * 33.52 m³ * 9.8 m/s² = 328496 N

The tension in the cable is the calculated as below;

Tension in the cable = Weight of object in air - upthrust/bouyancy due to the liquid

Tension in cable = 919788.8 N - 328.496 N = 591292.8 N

Therefore, tension in the cable is 591292.8 N or 591.3 kN

5 0
2 years ago
Which changes in an electric motor will make the motor stronger? Check all that apply. using a stronger permanent magnet using a
miv72 [106K]
Use stronger magnets
increase current
push magnets closer to coil
adding more sets of coils
4 0
3 years ago
Read 2 more answers
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