1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Nina [5.8K]
2 years ago
13

Help solve #25-29 pls help me !!!

Mathematics
1 answer:
koban [17]2 years ago
5 0
I think -4 is the answer
You might be interested in
Two blocks are connected by a very light string passing over a massless and frictionless pulley. The 20.0 N block moves 75.0cm t
Angelina_Jolie [31]
The string is assumed to be massless so the tension is the sting above the 12.0 N block has the same magnitude to the horizontal tension pulling to the right of the 20.0 N block. Thus, 
1.22 a = 12.0 - T  (eqn 1)
and for the 20.0 N block: 
2.04 a = T - 20.0 x 0.325 (using µ(k) for the coefficient of friction) 
2.04 a = T - 6.5  (eqn 2) 

[eqn 1] + [eqn 2] → 3.26 a = 5.5 
a = 1.69 m/s² 


Subs a = 1.69 into [eqn 2] → 2.04 x 1.69 = T - 6.5 
T = 9.95 N 

Now want the resultant force acting on the 20.0 N block: 
Resultant force acting on the 20.0 N block = 9.95 - 20.0 x 0.325 = 3.45 N 
<span>Units have to be consistent ... so have to convert 75.0 cm to m: </span>

75.0 cm = 75.0 cm x [1 m / 100 cm] = 0.750 m 
<span>work done on the 20.0 N block = 3.45 x 0.750 = 2.59 J</span>
3 0
2 years ago
Find the direction cosines and direction angles of the vector. (Give the direction angles correct to the nearest degree.) 5, 1,
Dahasolnce [82]

Answer:

The direction cosines are:

\frac{5}{\sqrt{42} }, \frac{1}{\sqrt{42} }  and  \frac{4}{\sqrt{42} }  with respect to the x, y and z axes respectively.

The direction angles are:

40°,  81° and  52° with respect to the x, y and z axes respectively.

Step-by-step explanation:

For a given vector a = ai + aj + ak, its direction cosines are the cosines of the angles which it makes with the x, y and z axes.

If a makes angles α, β, and γ (which are the direction angles) with the x, y and z axes respectively, then its direction cosines are: cos α, cos β and cos γ in the x, y and z axes respectively.

Where;

cos α = \frac{a . i}{|a| . |i|}               ---------------------(i)

cos β = \frac{a.j}{|a||j|}               ---------------------(ii)

cos γ = \frac{a.k}{|a|.|k|}             ----------------------(iii)

<em>And from these we can get the direction angles as follows;</em>

α =  cos⁻¹ ( \frac{a . i}{|a| . |i|} )

β = cos⁻¹ ( \frac{a.j}{|a||j|} )

γ = cos⁻¹ ( \frac{a.k}{|a|.|k|} )

Now to the question:

Let the given vector be

a = 5i + j + 4k

a . i =  (5i + j + 4k) . (i)

a . i = 5         [a.i <em>is just the x component of the vector</em>]

a . j = 1            [<em>the y component of the vector</em>]

a . k = 4          [<em>the z component of the vector</em>]

<em>Also</em>

|a|. |i| = |a|. |j| = |a|. |k| = |a|           [since |i| = |j| = |k| = 1]

|a| = \sqrt{5^2 + 1^2 + 4^2}

|a| = \sqrt{25 + 1 + 16}

|a| = \sqrt{42}

Now substitute these values into equations (i) - (iii) to get the direction cosines. i.e

cos α = \frac{5}{\sqrt{42} }

cos β =  \frac{1}{\sqrt{42} }              

cos γ =  \frac{4}{\sqrt{42} }

From the value, now find the direction angles as follows;

α =  cos⁻¹ ( \frac{a . i}{|a| . |i|} )

α =  cos⁻¹ ( \frac{5}{\sqrt{42} } )

α =  cos⁻¹ (\frac{5}{6.481} )

α =  cos⁻¹ (0.7715)

α = 39.51

α = 40°

β = cos⁻¹ ( \frac{a.j}{|a||j|} )

β = cos⁻¹ ( \frac{1}{\sqrt{42} } )

β = cos⁻¹ ( \frac{1}{6.481 } )

β = cos⁻¹ ( 0.1543 )

β = 81.12

β = 81°

γ = cos⁻¹ ( \frac{a.k}{|a|.|k|} )

γ = cos⁻¹ (\frac{4}{\sqrt{42} })

γ = cos⁻¹ (\frac{4}{6.481})

γ = cos⁻¹ (0.6172)

γ = 51.89

γ = 52°

<u>Conclusion:</u>

The direction cosines are:

\frac{5}{\sqrt{42} }, \frac{1}{\sqrt{42} }  and  \frac{4}{\sqrt{42} }  with respect to the x, y and z axes respectively.

The direction angles are:

40°,  81° and  52° with respect to the x, y and z axes respectively.

3 0
3 years ago
Candice buys 2/8 of a container of roasted peanuts. Alan buys 2/3 of a container. Both containers are the same size. Candice say
xz_007 [3.2K]

Since my name is in this question, I'll answer it :)

Answer:

Yes, she's right.

Step-by-step explanation:

2/8 is simplified to 1/4. Between 1 and 1/2, it is 1/4. So yes, I (Candice) was right. :)

5 0
2 years ago
Which of the following indicates the subtraction property of equality when solving the equation 4(x + 9) + 5 = 3x − 8? Question
jeka94

Answer: 4(x + 9) = 3x − 8 − 5

Step-by-step explanation:

Hi, to answer this question we have to analyze the equation given:

4(x + 9) + 5 = 3x − 8

The subtraction property of equality states that if we subtract the same number from both sides of the equation, the equality remains.

So, if we subtract 5 from both sides:

4(x + 9) + 5-5 = 3x − 8 -5

4(x + 9) = 3x − 8 − 5  

Feel free to ask for more if needed or if you did not understand something.

8 0
3 years ago
Can anyone solve this . Please tell the method as well
Zolol [24]
2^7b = 2^5

Now you have like bases. This means that you can set the exponents equal , meaning 7b= 5. B =5\7
5 0
2 years ago
Other questions:
  • There are 5 boxes of books in the storeroom each box has 78 books. how many books are there in all
    15·2 answers
  • Which equation shows the substitution method being used to solve the system of linear equations?
    7·2 answers
  • Find y if y = -7x -6 and x=5
    10·2 answers
  • Which of the following best describes the expression 2a + 3b + 4c + 5d?
    5·2 answers
  • Two triangles with the same corresponding side lengths will be congruent is known as the ____.
    15·1 answer
  • Temperature Change In Detroit the temperature is 69F and is rising at a rate of 2F per hour. In Atlanta the temperature is 84F a
    11·1 answer
  • The area of the rectangle on the bottom of this stack is 6 cm2 and the height of the stack is 3 cm. What is the volume of this r
    5·1 answer
  • In the figure below, ab is congruent to bc, and ae intersects bf at c. what is the measurement of
    13·1 answer
  • Each of Sunil's beagle puppies weighs less than 11.3 oz at birth.
    11·1 answer
  • Help please!
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!