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Usimov [2.4K]
3 years ago
11

A concrete block is pulled 7.0 m across a frictionless surface by means of a rope. The tension in the rope is 40 N; and the net

work done on the block is 247 J. What angle does the rope make with the horizontal?
Physics
1 answer:
Arturiano [62]3 years ago
5 0

Answer:

Explanation:

ΣF = ma

Also, work done is given by

W=F.d

Then, applying scalar product

W=FdCos θ

Given that W=247J, d=7m, and F=T=40N

Then,

W=FdCos θ

247=40×7Cos θ

Then,

Cos θ=0.8821

θ=arccos(0.8821 )

θ=28.1°

The angle the rope make with the horizontal is 28.1°

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Answer:

227 m/s

Explanation:

Kinetic energy formula:

  • \displaystyle \text{KE} = \frac{1}{2} mv^2
  • where m = mass of the object (kg)
  • and v = speed of the object (m/s)

Let's find the kinetic energy of the 145-g baseball moving at 31.0 m/s.

First convert the mass to kilograms:

  • 145-g → 0.145 kg

Plug known values into the KE formula.

  • \displaystyle \text{KE} = \frac{1}{2} (.145)(31.0)^2
  • \displaystyle \text{KE} = 69.6725 \ \text{J}

Now we want to find how fast a 2.70-g ping pong ball must move in order to achieve a kinetic energy of 69.6725 J.

First convert the mass to kilograms:

  • 2.70-g → 0.00270 kg

Plug known values into the KE formula.

  • \displaystyle 69.6725 = \frac{1}{2} (.00270)v^2
  • \displaystyle \frac{2(69.6725)}{.00270} =v^2
  • 57609.25926=v^2
  • v=227.1767137

The ping-pong ball must move at a speed of 227 m/s to achieve the same kinetic energy as the baseball.

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Which of the following situations is an example of environmental racism? A. Toxic facilities are usually located in the poorer a
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I have a question that's confusing, Will a large can of solids or empty can reach end of the ramp faster first in a can race? Al
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The large can of solids will reach before the empty can reason being is it has more additional weight its like dropping a 1 pound weight compared to a 4 pound the 4 pound reaches faster because of the gravitational pull the size of the pull depends on the masses of the objects 
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A coil of 10 turns is in the shape of an ellipse having a major axis of 13.0 cm and a minor axis of 6.00 cm. The coil rotates at
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Answer:

the maximum voltage induced in the coil is 2.574 × 10⁻⁵ V

Explanation:

Given the data in the question;

Number of turns N = 10

major axis Ma = 13 cm = 0.13 m

a = 0.13/2 = 0.065 m

Minor axis Mi = 6 cm = 0.06 m

b = 0.06/2 = 0.03 m

we know that; 1 RPM = 0.10472 rad/s

rate of rotation R = 73rpm = 7.64 rad/s

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we know that, Area of ellipse = π × a × b

we substitute

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we substitute

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