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In-s [12.5K]
2 years ago
11

a student raises a 4kg ball to an unknown height on a building. It is calculated that the ball has a speed of 30m/s when it hits

the ground. Calculate the height it fell from using the law of conversion of energy and the potential and kinetic energy questions

Physics
1 answer:
dedylja [7]2 years ago
4 0

Answer:

45.91 m

Explanation:

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A positive force on the balance indicates a downward force on the silver sphere while a negative force on the balance indicates
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The two spheres have opposite charges.

<h3 /><h3 /><h3>What are types charge?</h3>
  • A charge can be negatively charged or positively charged.
  • When two charges have opposite signs, that is positive and negative signs, the two charges will attract each other.
  • When the two charges have the same sign, it causes repulsion.

When a positive charge points downwards ↓ and the negative charge points upwards ↑, this causes attraction and shows that the two charges are different.

Thus, we can conclude that the two spheres have opposite charges.

Learn more about attraction and repulsion of charges here: brainly.com/question/2396080

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Symptoms of excessive stress include all of the following EXCEPT:
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Answer:

Symptoms of excessive stress include all of the following EXCEPT: increased energy level.

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2 years ago
If the coefficient of friction is 0.3900 and the cylinder has a radius of 2.700 m, what is the minimum angular speed of the cyli
Aleks04 [339]

Answer:

w=3.05 rad/s or 29.88rpm

Explanation:

k = coefficient of friction = 0.3900

R = radius of the cylinder = 2.7m

V = linear speed of rotation of the cylinder

w = angular speed = V/R or to rewrite V = w*R

N = normal force to cylinder

N==\frac{m(V)^{2}}{R}=m*(w)^2*R

Friction force\\Ff = k*N\\Ff= k*m*w^2*R

Gravitational force \\Fg = m*g

These must be balanced (the net force on the people will be 0) so set them equal to each other.

Fg = Ff

m*g = k*m*w^2*R

g=k*w^{2}*R

w^2 =\frac{g}{k*R}

w=\sqrt{\frac{g}{k*R}} \\w =\sqrt{\frac{9.8\frac{m}{s^{2}}}{0.3900*2.7m}}\\ w=\sqrt{9.306}=3.05 \frac{rad}{s}

There are 2*pi radians in 1 revolution so:

RPM=\frac{w}{2\pi }*60\\RPM=\frac{3.05\frac{rad}{s}}{2\pi}*60\\RPM= 0.498*60\\RPM=29.88

So you need about 30 RPM to keep people from falling out the bottom

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3 years ago
What type of atom is K2CO3
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<span>Potassium carbonate (K2C03) is white salt and is often </span>found damp. It is soluble in water which makes a strong concoction. Hope this helps.
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Why is there no drag in space?????? Help me please!!! Thanks!!!
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It is beacuse of fluid If there is no fluid, there is no drag. Drag is generated by the difference in velocity between the solid object and the fluid. If this statement is correct then how can there be drag in space if there is no air?
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