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
oee [108]
3 years ago
9

An object of mass 6 kg. is resting on a horizontal surface. A horizontal force

Physics
1 answer:
son4ous [18]3 years ago
7 0

Answer:

a) The work done by the applied force is 1500 joules.

b) The kinetic energy of the block after 10 seconds is 1200 joules.

c) The magnitude of the force of friction is 3 newtons and its direction is against motion.

d) 300 joules of energy are lost during motion.

Explanation:

a) Since the object has a constant mass, on which a constant horizontal force is exerted. The work done by the force (W), measured in joules, is defined by the following expression:

W = F\cdot \Delta x (1)

Where:

F - Force, measured in newtons.

\Delta x - Distance, measured in meters.

If we know that F = 15\,N and \Delta x = 100\,m, then the work done by the force exerted on the object is:

W = (15\,N)\cdot (100\,m)

W = 1500\,J

The work done by the applied force is 1500 joules.

b) At first we need to calculate the net acceleration of the object (a), measured in meters per square second. By assuming a constant acceleration, we use the following kinematic formula:

\Delta x = v_{o}\cdot t +\frac{1}{2}\cdot a\cdot t^{2} (2)

Where v_{o} is the initial velocity of the object, measured in meters per second.

We clear the acceleration within the equation above:

\frac{1}{2}\cdot a \cdot t^{2} =  \Delta x-v_{o}\cdot t

a = \frac{2\cdot (\Delta x - v_{o}\cdot t)}{t^{2}}

If we know that \Delta x = 100\,m, v_{o} = 0\,\frac{m}{s} and t = 10\,s, then the net acceleration experimented by the object is:

a = \frac{2\cdot \left[100\,m-\left(0\,\frac{m}{s} \right)\cdot (10\,s)\right]}{(10\,s)^{2}}

a = 2\,\frac{m}{s^{2}}

By the 2nd Newton's Law, we construct the following equation of equilibrium under the consideration of a friction force acting against the motion of the object:

\Sigma F = F - f = m\cdot a (3)

Where:

F - External force exerted on the object, measured in newtons.

f - Kinetic friction force, measured in newtons.

If we know that F = 15\,N, m = 6\,kg and a = 2\,\frac{m}{s^{2}}, the kinetic friction force is:

f = F-m\cdot a

f = 15\,N-(6\,kg)\cdot \left(2\,\frac{m}{s^{2}} \right)

f = 3\,N

The work done by friction (W'), measured in joules, is:

W' = f\cdot \Delta x (4)

W' = (3\,N) \cdot (100\,m)

W' = 300\,J

And the net work experimented by the object is:

\Delta W = 1500\,J - 300\,J

\Delta W = 1200\,J

By the Work-Energy Theorem we understand that change in translational kinetic energy (\Delta K), measured in joules, is equal to the change in net work. That is:

\Delta K = \Delta W (5)

If we know that \Delta W = 1200\,J, then the change in translational kinetic energy is:

\Delta K = 1200\,J

The kinetic energy of the block after 10 seconds is 1200 joules.

c) The magnitude of the force of friction is 3 newtons and its direction is against motion.

d) The energy lost by the object is equal to the work done by the force of friction. Therefore, 300 joules of energy are lost during motion.

You might be interested in
A student constructed a series circuit consisting of a 12.0-volt battery, a 10.0-ohm lamp, and a
vesna_86 [32]

I thought you were going to ask for the resistance of the unknown
series resistor.  Since you only want the equivalent resistance of the
circuit, you don't even need to know the resistance of the lamp.

I = E / R

Current through the circuit = (voltage of the battery) / (circuit resistance).
  
                                                  0.5 = (12) / R

Multiply each side by  'R' :    (0.5) R = 12

Multiply each side by  2 :      <em>R = 24 ohms</em>


(Since the resistance of the lamp is 10 ohms, the
unknown series resistor is the other 14 ohms.)
7 0
3 years ago
A pump lifts 400 kg of water per hour a height of 4.5 m .
nasty-shy [4]

Answer:

Power = Work / Time

P = 400 kg * 9.8 m/s * 4.5 m / 3600 sec = 4.9 J/s = 4.9 Watts

Also, 4.9 Watts / (746 Watts / Horsepower) = .0066 Hp

6 0
2 years ago
Three forces act on a moving object. One force has a magnitude of 83.7 N and is directed due north. Another has a magnitude of 5
LekaFEV [45]

Answer:

  • |\vec{F}_3| = 102.92 \ N
  • \theta = 57 \° 24 ' 48''

Explanation:

For an object to move with constant velocity, the acceleration of the object must be zero:

\vec{a} = \vec{0}.

As the net force equals acceleration multiplied by mass , this must mean:

\vec{F}_{net} = m \vec{a} = m * \vec{0} = \vec{0}.

So, the sum of the three forces must be zero:

\vec{F}_1 + \vec{F}_2 + \vec{F}_3 = \vec{0},

this implies:

\vec{F}_3  = - \vec{F}_1 - \vec{F}_2.

To obtain this sum, its easier to work in Cartesian representation.

First we need to define an Frame of reference. Lets put the x axis unit vector \hat{i} pointing east,  with the y axis unit vector \hat{j} pointing south, so the positive angle is south of east. For this, we got for the first force:

\vec{F}_1 = 83.7 \ N \ (-\hat{j}),

as is pointing north, and for the second force:

\vec{F}_2 = 59.9 \ N \ (-\hat{i}),

as is pointing west.

Now, our third force will be:

\vec{F}_3  = - 83.7 \ N \ (-\hat{j}) - 59.9 \ N \ (-\hat{i})

\vec{F}_3  =  83.7 \ N \ \hat{j}  + 59.9 \ N \ \hat{i}

\vec{F}_3  =  (59.9 \ N , 83.7 \ N )

But, we need the magnitude and the direction.

To find the magnitude, we can use the Pythagorean theorem.

|\vec{R}| = \sqrt{R_x^2 + R_y^2}

|\vec{F}_3| = \sqrt{(59.9 \ N)^2 + (83.7 \ N)^2}

|\vec{F}_3| = 102.92 \ N

this is the magnitude.

To find the direction, we can use:

\theta = arctan(\frac{F_{3_y}}{F_{3_x}})

\theta = arctan(\frac{83.7 \ N }{ 59.9 \ N })

\theta = 57 \° 24 ' 48''

and this is the angle south of east.

7 0
2 years ago
A sample of an ideal gas initially occupies a volume of 6 L. The pressure of the sample is then doubled while it is cooled to on
Troyanec [42]

Answer:

V₂= 1 L

Explanation:

Given that

Volume occupies V₁= 6 L

Initial pressure = P₁

Initial temperature = T₁

The final pressure =P₂ = 2 P₁

Final volume =V₂

Final temperature = T₁/3

As we know that equation for ideal gas

P V = m R T

P=pressure,  V=volume,   T=temperature

m=mass  ,R=gas constant

Now from mass conservation

m=\dfrac{P_1V_1}{RT_1}=\dfrac{P_2V_2}{RT_2}

\dfrac{P_1V_1}{RT_1}=\dfrac{P_2V_2}{RT_2}

\dfrac{P_1\times 6}{RT_1}=3\times \dfrac{2P_1V_2}{RT_1}

6 = 3 x 2 V₂

V₂= 1 L

So the final volume will be 1 L

4 0
3 years ago
- Explain why an aircraft will tend to lose height
olganol [36]

Answer:

the planes wings are lifting  at an angle to gravity so the plane isn't lifting as much against gravity when it banks.  some of the wing lift is going into turning the plane.   :)   so it needs more lift to bank and stay up

Explanation:

8 0
2 years ago
Other questions:
  • 5. There was less work done. Which of the statements describes how this is possible? (2 points) There was less force applied or
    13·2 answers
  • (01.02 MC) Nicole pushes her bike up a hill. Overhead, the sun exerts a gravitational force on Earth. Which statement is true ab
    9·2 answers
  • What is it called when a falling object stops accelerating while it is still falling?
    6·1 answer
  • A force on a particle depends on position such that f(x) = (3.00 n/m2)x 2 + (3.50 n/m)x for a particle constrained to move along
    11·2 answers
  • What information is needed to determine the orientation of an orbital?
    6·1 answer
  • How do you open a door if its not locked?
    6·1 answer
  • Sayid made a chart listing data of two colliding objects.
    10·1 answer
  • Relative to a stationary observer, a moving clock Group of answer choices can do any of the above. It depends on the relative en
    6·1 answer
  • Describe the forces that are acting on a person who is standing still on a sidewalk, and identify whether the forces are balance
    6·1 answer
  • Is the answer 1.05m?? help me please. i just want to confrim my answer :3
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!