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
Maksim231197 [3]
3 years ago
7

John doe gets on the highway in his 1967 Shelby 427 Cobra starting from the dead stop at the bottom of the on ramp of it can be

assumed that John accelerates at a rate of 6.7 m s2 how long does it take for John to reach the speed of 30 m s?
Physics
1 answer:
masha68 [24]3 years ago
7 0

Answer:

It will take john 4.477 seconds

You might be interested in
Block B is attached to a massless string of length L = 1 m and is free to rotate as a pendulum. The speed of block A after the c
Amanda [17]

Complete Question

The diagram for this question is shown on the first uploaded image

Answer:

The minimum velocity of A is  v_A= 4m/s

Explanation:

From the question we are told that

    The length of the string is  L = 1m

     The initial speed of block A is u_A

     The final speed of block A is  v_A = \frac{1}{2}u_A

      The initial speed of block B is u_B = 0

      The mass of block A  is  m_A = 7kg  gh

      The mass of block B is  m_B  = 2 kg

According to the principle of conservation of momentum

       m_A u_A + m_B u_B = m_Bv_B + m_A \frac{u_A}{2}

Since block B at initial is at rest

       m_A u_A  = m_Bv_B + m_A \frac{u_A}{2}

      m_A u_A  - m_A \frac{u_A}{2} = m_Bv_B

          m_A \frac{u_A}{2} = m_Bv_B

  making v_B the subject of the formula

             v_B =m_A \frac{u_A}{2 m_B}

Substituting values

               v_B =\frac{7 u_A}{4}  

This v__B is the velocity at bottom of the vertical circle just at the collision with mass A

Assuming that block B is swing through the vertical circle(shown on the second uploaded image ) with an angular velocity  of v__B' at  the top of the vertical circle  

 The angular centripetal acceleration  would be mathematically represented

                   a= \frac{v^2_{B}'}{L}

Note that  this acceleration would be toward the center of the circle

      Now the forces acting at the top of the circle can be represented mathematically as

         T + mg = m \frac{v^2_{B}'}{L}

    Where T is the tension on the string

  According to the law of energy conservation

The energy at  bottom of the vertical circle   =  The energy at the top of

                                                                                the vertical circle

   This can be mathematically represented as

                 \frac{1}{2} m(v_B)^2 = \frac{1}{2} mv^2_B' + mg 2L

From above  

                (T + mg) L = m v^2_{B}'

Substitute this into above equation

             \frac{1}{2} m(\frac{7 v_A}{4} )^2 = \frac{1}{2} (T + mg) L  + mg 2L  

             \frac{49 mv_A^2}{16}  = \frac{1}{2} (T + mg) L + mg 2L

          \frac{49 mv_A^2}{16}  = T + 5mgL

The  value of velocity of block A needed to cause B be to swing through a complete vertical circle is would be minimum when tension on the string due to the weight of B is  zero

        This is mathematically represented as

                      \frac{49 mv_A^2}{16}  = 5mgL

making  v_A the subject

            v_A = \sqrt{\frac{80mgL}{49m} }

substituting values

          v_A = \sqrt{\frac{80* 9.8 *1}{49} }

              v_A= 4m/s

     

6 0
3 years ago
the speed of sound in the air is about 340m/s. what is the wavelength of a sound wave with a frequency of 400Hz?
olga2289 [7]

Wavelength = (speed) / (frequency)

Wavelength = (340 m/s) / (400 /s)

<em>Wavelength = 0.85 meter</em>

5 0
3 years ago
A water pipe having a 4.00 cm inside diameter carries water into the basement of a house at a speed of 1.00 m/s and a pressure o
posledela

Answer:

8.16\ \text{m/s}

Explanation:

d_1 = Initial diameter = 4 cm

v_1 = Initial velocity = 1 m/s

d_2 = Final diameter = 7.8 m

v_2 = Final velocity

A = Area = \pi\dfrac{d^2}{4}

From the continuity equation we get

A_1v_1=A_2v_2\\\Rightarrow \pi\dfrac{d_1^2}{4}v_1=\pi\dfrac{d_2^2}{4}v_2\\\Rightarrow v_2=\dfrac{d_1^2}{d_2^2}v_1\\\Rightarrow v_2=\dfrac{4^2}{1.4^2}\times 1\\\Rightarrow v_2=8.16\ \text{m/s}

The speed of water at the second floor is 8.16\ \text{m/s}.

8 0
3 years ago
How many atoms of hydrogen in the product side of the balanced equation
Anettt [7]

The same number there were on the reactant side, before the reaction.

6 0
3 years ago
What is the value of x in the triangle? a 45-45-90 triangle with leg length x and hypotenuse length 4
mrs_skeptik [129]

Answer:

x = 2\sqrt 2

Explanation:

Given

Hypotenuse = 4

Required

Find x

Since the triangle is a 45-45-90 triangle, the following relationship exists

x^2 + x^2 = 4^2 --- i.e. the other legs are equal

So, we have:

2x^2 = 16

Divide both sides by 2

x^2=8

Take square roots of both sides

x = \sqrt 8

Simplify

x = 2\sqrt 2

5 0
2 years ago
Read 2 more answers
Other questions:
  • Calculate the speed of an 8.0x10^4 kg airliner with a kinetic energy of 1.1x10^9 j ...?
    11·1 answer
  • A 535 kg roller coaster car began at rest at the top of a 93.0 m hill. Now it is at the top of the first loop-de-loop. This roll
    11·1 answer
  • Marcia pokes fun at her husband Brian because he loves to sing in the shower every morning, but
    13·1 answer
  • In what form does carbon return to the atmosphere after it is released from the burning of fossil fuels
    6·1 answer
  • A tungsten wire has resistance R at 20°C. A second tungsten wire at 20°C has twice the length and half the cross-sectional area
    8·1 answer
  • Pendulum clocks are made to run at the correct rate by adjusting the pendulum’s length. Suppose you move from one city to anothe
    6·1 answer
  • Pls help i’ll give brainliest if you give a correct answer!!
    15·2 answers
  • A frictionless pulley used to lift 8000N of concrete. What is the minimum effort required to raise the block
    11·1 answer
  • Why a small car can stop easier than an 18 wheeler while traveling at 70 mph down the interstate?
    11·1 answer
  • A mass is attached to a spring with an unknown spring constant. The spring gains 10 J of elastic potential energy if stretched b
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!