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
maria [59]
3 years ago
5

A 6 kg block initially at rest is pulled to East along a horizontal surface with coefficient of kinetic friction μk=0.15 by a co

nstant horizontal force of 12 N. Find the speed of the block after it has moved 3m.
Physics
1 answer:
ozzi3 years ago
8 0

Answer:

1.8 m/s

Explanation:

Draw a free body diagram of the block.  There are four forces:

Normal force Fn up.

Weight force mg down.

Applied force F to the east.

Friction force Fn μ to the west.

Sum the forces in the y direction:

∑F = ma

Fn − mg = 0

Fn = mg

Sum the forces in the x direction:

F − Fn μ = ma

F − mg μ = ma

a = (F − mg μ) / m

a = (12 N − 6 kg × 9.8 m/s² × 0.15) / 6 kg

a = 0.53 m/s²

Given:

Δx = 3 m

v₀ = 0 m/s

a = 0.53 m/s²

Find: v

v² = v₀² + 2aΔx

v² = (0 m/s)² + 2 (0.53 m/s²) (3 m)

v = 1.8 m/s

You might be interested in
What are 3 things top students do differently
givi [52]

Answer:

Learn

Focus

Time management

Explanation:

3 0
3 years ago
Scientists who study races and their origins are called
trapecia [35]
The answer is B. Bye because B those study speed.
6 0
3 years ago
Read 2 more answers
A 5 kg wooden block sitson a flat straight-away12 meters fromthe bottom of an infinitely long ramp, which has an angle of 20 deg
saveliy_v [14]

Answer:

(a) 19.71801m/s Velocity just before going up the ramp.

(b) 74.56338m.

Explanation:

We will solve it in two parts, first we will calculate time that 5kg wooden block would take to just reach ramp and with this time we will calculate final velocity that the wooden block would have in this time.

Second, we will calculate the component of velocity vector along inclined plane and the time that it would take for velocity to be 0 meters/s then with this time we will calculate the distance that inclined plane would travel along inclined plane.

Following formulas will be used.

                                  x(t) = \frac{1}{2} t^2 = 12m =16.2m/s^2 t^2

                                 F =ma

                                 V(t) = V_{o} +at

                                 x(t) = x_{0} +v_{0}t+\frac{1}{2}a t^2

(a) Calculating velocity right before going up the ramp.

 Wooden block is going on a straightaway and has net for on it.

         F_{n} =F-F_{s} = F-uF_{n}  = 100N-0.4*9.8m/s^2*5kg =81N

     and this force produces acceleration of

      a = \frac{F}{m}=\frac{81}{5} =16.2m/s^2 .

With this acceleration, wooden block would reach at the foot of ramp in.

          x(t) = 12m = 16.2m/s^2*t^2

         t = 1.217s

and final velocity will be

v(t) = v_{0}+at = 0+16.2m/s^2*1.2171s = 19.7180m/s.

this velocity of wooden box just before going up the ramp.

(b) How far up the ramp will the wooden block go before stopping.

Ramp is at 20° relative to horizontal therefore velocity along the ramp that the wooden block would have will be.

                              V= V_{h}cos(20) = 18.5288m/s

and deceleration along the ramp is

                              a = \frac{F_{s} }{m}

 Where F_{s} force of friction along the inclined plane.

F_s =  uF_n = u*m*a

a = 9.8m/s^2*cos(20) = 9.2089m/s^2

is a component of g along normal of the inclined plane.

                               F_{s} = 0.25*5kg*9.2089m/s^2

                              = 11.5112N

                              a = \frac{11.5112N}{5kg} = 2.3022m/s^2

And with this deceleration time needed to get wooded block to stop is.

                     v(t) = v_o-at = 18.5288m/s-2.3022m/s^2*t = 0

                        t = \frac{18.5288m/s}{2.3022m/s^2} =8.04813s

 and in that time wooden block would travel

   x(8.04813s) = 18.52881m/s *8.04813s-\frac{1}{} 2.3022m/s^2*(8.0481)^2=74.56338m

This is how up wooden box will go before coming to stop.

3 0
3 years ago
A voltage of 220V (rms) line to netralvoltage is applied across a three phase Y connected resistive load. Each phase of the Y co
mrs_skeptik [129]

Answer:

Current through each phase Vp = 2.2A

Total three phase power Pt= 1.45kW

Power factor of the load pf = 1

Explanation:

i) Find current through each phase

Vp =220V (rms)

Z =100 Ω

I = Vp/Z

 = 220/100

 = 2.2A

ii) Find the total three phase power

for a resistive load, Power, P = VI

Power for each phase is given as:

P = 220 * 2.2

  = 484 W

Total power TP =3* P

                          =484*3

                          = 1452W

                           =1.45kW

 iii) Find the power factor of the load

Phase angle for a resistive load is 0.

α= 0

Hence, power factor of load = cos α

                                          pf      = cos 0

                                             pf    = 1

5 0
3 years ago
Which of the following shows the units of angular motion?
Whitepunk [10]

Answer:

  • The units are <em>(</em><em>rad</em><em>/</em><em>s</em><em>^</em><em>2</em><em>)</em><em> </em>
4 0
3 years ago
Other questions:
  • Calculate the acceleration of a 25 kg object that has move the force of 300 n
    12·1 answer
  • 21. True or false: During heat transfer heat always travels from the warmer object to the cooler object.
    13·1 answer
  • In most cases, what happens to a liquid when it cools?
    11·1 answer
  • The _____ law of thermodynamics states that energy can't be created or destroyed. Two natural sources of energy on Earth are the
    6·2 answers
  • A 74.9 kg person sits at rest on an icy pond holding a 2.44 kg physics book. he throws the physics book west at 8.25 m/s. what i
    13·1 answer
  • What is an important difference between medieval muslim and christian art?
    15·1 answer
  • A wire of length L and cross-sectional area A has resistance R.
    8·2 answers
  • what would be a very very very very very GOOD science project the the COUNTY SCIENCE FAIR!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    9·2 answers
  • 5. Describe Mendel’s first set of experiments
    10·1 answer
  • What would be the greatest effect of the finite size of molecules on the ideal gas law?
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!