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
DanielleElmas [232]
3 years ago
7

a 1811kg car speeds up from rest when a traffic light turns green until it reaches a speed of 23m/s. how much work was done on t

he car by friction?
Physics
1 answer:
sattari [20]3 years ago
3 0

Answer:

The work done by the frictional force, W = 612565.32 J

Explanation:

Given data,

The mass of the car, m = 1811 kg

The initial velocity of the car, u = 0 m/s

The final velocity of the car, v = 23 m/s

Let the time period of the car be, t = 3 s

The acceleration of the car,

                              a = (v-u) /t

                                 = (23 - 0)/ 3

                                = 7.67 m/s²

The normal force acting on the car,

                         F = mg

                             = 1811 kg x 9.8 m/s²

                              = 17747.8 N

The displacement of the car,

                             s = ut + ½ at²

                                 = 0 + ½ x 7.67 x 3²

                                 = 54.52 m

The work done by the frictional force,

                              W = F · S

                              W = 17747.8 N x 54.52 m

                                   = 612565.32 J

Hence, the work done by the frictional force, W = 612565.32 J

You might be interested in
What physical property makes the red light different from blue light, or radio waves different from microwaves?​
inna [77]

Only their wavelength does.

Blue light waves have only roughly half the wavelength of red light waves, and the so-called "microwaves" are the radio waves with the shortest wavelengths.

4 0
3 years ago
Read 2 more answers
A swinging pendulum has a total energy of <img src="https://tex.z-dn.net/?f=E_i" id="TexFormula1" title="E_i" alt="E_i" align="a
Zolol [24]

Answer:

\frac{E_{2}}{E_{1}} \approx 1 -\frac{3\theta}{1-\theta} (for small oscillations)

Explanation:

The total energy of the pendulum is equal to:

E_{1} = m\cdot g \cdot (1-\cos \theta)\cdot L

For small oscillations, the equation can be re-arranged into the following form:

E_{1} \approx m\cdot g \cdot (1-\theta) \cdot L

Where:

\theta = \frac{A}{L^{2}}, measured in radians.

If the amplitude of pendulum oscillations is increase by a factor of 4, the angle of oscillation is 4\theta and the total energy of the pendulum is:

E_{2} \approx m\cdot g \cdot (1-4\theta)\cdot L

The factor of change is:

\frac{E_{2}}{E_{1}} \approx \frac{1 - 4\theta}{1-\theta}

\frac{E_{2}}{E_{1}} \approx 1 -\frac{3\theta}{1-\theta}

3 0
3 years ago
Two forces are applied on a body. One produces a force of 480-N directly forward while the other gives a 513-N force at 32.4-deg
n200080 [17]

Answer:

F = (913.14 , 274.87 )

|F| = 953.61 direction 16.71°

Explanation:

To calculate the resultant force you take into account both x and y component of the implied forces:

\Sigma F_x=480N+513Ncos(32.4\°)=913.14N\\\\\Sigma F_y=513sin(32.4\°)=274.87N

Thus, the net force over the body is:

F=(913.14N)\hat{i}+(274.87N)\hat{j}

Next, you calculate the magnitude of the force:

F=\sqrt{(913.14N)+(274.87N)^2}=953.61N

and the direction is:

\theta=tan^{-1}(\frac{274.14N}{913.14N})=16.71\°

7 0
3 years ago
In an experiment, students measure the position x of a cart as a function of time t for a cart that starts at rest and moves wit
Minchanka [31]

Given :

Initial velocity , u = 0 m/s² .

To Find :

The acceleration of the cart.

Solution :

Since, acceleration is constant.

Using equation of motion :

x = ut + \dfrac{at^2}{2}\\\\x = \dfrac{at^2}{2}

Putting, t = 1 s  and x = 4 m in above equation, we get :

4 = \dfrac{a(1)^2}{2}\\\\a = 8 \  m/s^2

Therefore, the acceleration of the cart is 8 m/s².

5 0
3 years ago
Alcohol of mass 33.2g and density 0.79kg/m³ or 790kg/m³ is mixed with water of 9g. What is the density of the resulting mixture?
KATRIN_1 [288]

Answer:

  0.83 g/cm³

Explanation:

The volume of the alcohol is ...

  (33.2 g)/(0.79 g/cm³) ≈ 42.0253 cm³

The density of water is about 1 g/cm³, so the volume of 9 g of it is ...

  (9 g)/(1 g/cm³) = 9 cm³

The total volume is ...

  42.0253 cm³ +9 cm³ = 51.0253 cm³

The total mass is ...

  33.2 g + 9 g = 42.4 g

So, the resulting density is ...

  (42.4 g)/(51.0253 cm³) ≈ 0.83 g/cm³

The resulting mixture has a density of about 0.83 g/cm³.

_____

<em>Additional comment</em>

Alcohol dissolves in water, so the total volume will be slightly less than 51.0253 cm³. The attached curve shows the result of mixing ethanol and water.

The weight of a mole of ethanol is about 46 g, of water, about 18.02 g. Then the mole fraction of alcohol is ...

  (33.2/46)/(33.2/46 +9/18.02) ≈ 0.59

The volume of the mix is then estimated to be (-1.05 cc/mol)(1.221 mol), or about 1.28 cm³ less than the volume indicated above. That brings the density up to about 0.85 g/cm³.

We're not completely sure of the relevance of this calculation, since many of the applicable parameters are not specified. The point is that <em>the density of the mix will probably be slightly more than the value calculated above</em>. YMMV

3 0
3 years ago
Other questions:
  • A tuba may be treated like a tube closed at one end. If a tuba has a fundamental frequency of 88.4 Hz, determine the first three
    14·1 answer
  • When a 4.32 kg object is hung vertically on a certain light spring that obeys Hooke's Law, the spring stretches 2.92 cm.
    12·1 answer
  • The amount of water displaced, in water displacement method depends on the *
    6·1 answer
  • A 75.3 kg bobsled is pushed along a horizontal surface by two athletes. After the bobsled is pushed a distance of 8.1 m starting
    15·1 answer
  • Two objects attract each other with a gravitational force of magnitude 1.02 10-8 N when separated by 19.7 cm. If the total mass
    9·2 answers
  • Find the acceleration of the system and the tension in the ropes for the system shown. The table mass is 30 kg and the hanging m
    7·1 answer
  • A climber is attached to a vertical rope that has a tension of
    14·1 answer
  • a given box of 2 kg is in contact with the floor experiences an applied force of 150 form somebody pushing it.while in motion,it
    15·1 answer
  • A car is travelling to the right with a speed of 40 m/s when the driver slams on the brakes. The car skids for 4 s with constant
    9·1 answer
  • Un tren de alta velocidad (TAV) o tren bala es aquel que alcanza velocidades iguales o superiores a 200 km/h. La energía que tie
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!