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3 years ago

Can two people do different work, but have the same power?

2 answers:

8 0

Of course !

I lift 1 kilogram 1 meter in 1 second.
You lift 60 kilograms 2 meters in 2 minutes.

My work is 9.8 joules.
Your work is 1,176 joules.

My power is 9.8 watts.
Your power is also 9.8 watts.

Lelechka [254]3 years ago

7 0

Yes, two people can do different work and have the same power.

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An object with a mass m slides down a rough 370 inclined plane where the coefficient of kinetic friction is 0.20. If the plane i

Svetllana [295]

Answer:

$v \approx 9.312\,\frac{m}{s}$

Explanation:

The Free Body Diagram of the system is presented in the image attached below. The final speed is determined by means of the Principle of Energy Conservation and the Work-Energy Theorem:

$K_{A} + U_{g,A} = K_{B} + U_{g,B} + W_{loss}$

$K_{B} = K_{A} + U_{g,A}-U_{g,B} - W_{loss}$

$\frac{1}{2}\cdot m \cdot v^{2} = m\cdot g \cdot s\cdot \sin \theta - \mu_{k}\cdot m \cdot g \cdot s \cos \theta$

$\frac{1}{2}\cdot v^{2} = g\cdot s \cdot (\sin \theta - \mu_{k}\cdot \cos \theta)$

$v = \sqrt{2\cdot g \cdot s \cdot (\sin \theta - \mu_{k}\cdot \cos \theta)}$

$v = \sqrt{2\cdot (9.807\,\frac{m}{s^{2}} )\cdot (10\,m)\cdot (\sin 37^{\textdegree} - 0.2\cdot \cos 37^{\textdegree})}$

$v \approx 9.312\,\frac{m}{s}$

3 0

3 years ago

Two vehicles approach a right angle intersection and then suddenly collide. After the collision, they become entangled. If their

geniusboy [140]

Answer:

a. 11 m/s at 76° with respect to the original direction of the lighter car.

Explanation:

In this exercise, since both cars make a right angle, let's assume that the lighter car only has a horizontal velocity component (vx) and that the heavier one only has a vertical velocity component (vy). The final velocities for both components for the system can be determined as:

$m_{1} v_{x1}+m_{2}v_{x2}=(m_{1}+m_{2})v_{fx}\\m_{1} v_{y1}+m_{2}v_{y2} =(m_{1}+m_{2})v_{fy}$

Assume that the lighter car has a 1kg mass and that the heavier car has a 4 kg mass.

$1*13 + 4*0 = (1+4) v_{fx}\\v_{fx}=\frac{13}{5} =2.6\\1*0 + 4*13 = (1+4) v_{fy}\\v_{fy}=\frac{13*4}{5} =10.4\\$

The magnitude of the final velocity of the wreck can be found as:

$v_{f}^{2}= v_{fx}^{2}+ v_{fy}^{2}\\v_{f}=\sqrt[]{2.6^{2} + 10.4^{2}} \\v_{f}= 10.72$

The final velocity has an intensity of roughly 11 m/s

As for the angle, it can be determined in respect to the lighter car (x axis) as follows:

$\theta = cos^{-1}(\frac{v_{fx} }{v_{f}} )\\\theta = cos^{-1}(\frac{2.6}{10.7} )\\\theta = 76^{o}$

Therefore, the wreck has a velocity with an intensity of 11 m/s at 76° with respect to the original direction of the lighter car.

5 0

3 years ago

The Hubble Space Telescope (HST) orbits 569 km above Earth’s surface. Given that Earth’s mass is 5.97 × 1024 kg and its radius i

Sergio039 [100]

<span>We can use an equation to find the gravitational force exerted on the HST. F = GMm / r^2 G is the gravitational constant M is the mass of the Earth m is the mass of the HST r is the distance to the center of the Earth This force F provides the centripetal force for the HST to move in a circle. The equation we use for circular motion is: F = mv^2 / r m is the mass of the HST v is the tangential speed r is the distance to the center of the Earth Now we can equate these two equations to find v. mv^2 / r = GMm / r^2 v^2 = GM / r v = sqrt{GM / r } v = sqrt{(6.67 x 10^{-11})(5.97 x 10^{24}) / 6,949,000 m} v = 7570 m/s which is equal to 7.570 km/s HST's tangential speed is 7570 m/s or 7.570 km/s</span>

6 0

3 years ago

Read 2 more answers

Which property of light remains unchanged when it enters a different medium?

RideAnS [48]

B. Frequency remains unchanged because the energy in a photon is E=hf. So if the frequency changes so does the energy and that doesn't happen to EM waves entering a medium by the conservation of energy

7 0

3 years ago

Read 2 more answers

Which of the following statements are true?

Tems11 [23]

Answer:

1) A time-varying magnetic field will produce an electric field.

4) A time-varying electric field will produce a magnetic field.

Explanation:

1) A time-varying magnetic field will produce an electric field.

TRUE

time varying magnetic field will produce electric field which is given as

$E = \frac{r}{2}\frac{dB}{dt}$

2) Time-varying electric and magnetic fields can propagate through space only if there is no matter in their path.

FALSE

Time varying electric field and magnetic field will induce each other and it can travel through any medium as well as it can travel without any medium also

3) Electric and magnetic fields can be treated independently only if they vary in time.

FALSE

electric field can be due to stationary charge and magnetic field due to current carrying elements so it is not compulsory to have time varying

4) A time-varying electric field will produce a magnetic field.

TRUE

Time varying electric field will produce magnetic field given as

$B = \frac{\mu_o\epsilon_o A}{2r}\frac{dE}{dt}$

3 0

3 years ago