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3 years ago

An object is placed to the left of a convex mirror, such that the object-to-image distance is 140 cm.

Physics

1 answer:

labwork [276]3 years ago

6 0

Answer:

The focal length of the mirror is 52.5 cm.

Explanation:

Given that,

Object to Image distance d = 140 cm

Image distance v= 35 cm

We need to calculate the object distance

$u = d-v$

$u = 140-35=105\ cm$

We need to calculate the focal length

Using formula of mirror

$\dfrac{1}{f}=\dfrac{1}{u}+\dfrac{1}{v}$

Put the value into the formula

$\dfrac{1}{f}=\dfrac{1}{-105}+\dfrac{1}{35}$

$\dfrac{1}{f}=\dfrac{2}{105}$

$f=52.5\ cm$

Hence, The focal length of the mirror is 52.5 cm.

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Magnectic striping is evidence of ?

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Answer: Magnetizim

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3 years ago

Now the elevator is moving downward with a velocity of v = -2.8 m/s but accelerating upward with an acceleration of a = 5.5 m/s2

borishaifa [10]

Answer:

160.75 N

Explanation:

The downward velocity has no effect on the force situation, it is only changes in velocity (plus, of course, gravity, which is always there) that require a force. At constant velocity, the bottom spring s_3 is supporting its mass m_3 to balance gravity.

As the elevator slows, though, it also ends up slowing down the spring arrangement, too. However, because the stretching takes time, it means that some damped harmonic motion will be set up in the spring chain.

When the motion has finally damped out, the net force the bottom spring s3 exerts on m3 has two components--that of gravity and of the deceleration of the elevator:

F_3net = m3 * (g + a) = 10.5×(9.81+5.5)= 10.5×15.31= 160.75 N

5 0

3 years ago

A 16.2 kg person climbs up a uniform ladder with negligible mass. The upper end of the ladder rests on a frictionless wall. The

S_A_V [24]

To solve this problem we will apply the concepts related to the balance of forces. We will decompose the forces in the vertical and horizontal sense, and at the same time, we will perform summation of torques to eliminate some variables and obtain a system of equations that allow us to obtain the angle.

The forces in the vertical direction would be,

$\sum F_x = 0$

$f-N_w = 0$

$N_w = f$

The forces in the horizontal direction would be,

$\sum F_y = 0$

$N_f -W =0$

$N_f = W$

The sum of Torques at equilibrium,

$\sum \tau = 0$

$Wdcos\theta - N_wLsin\theta = 0$

$WdCos\theta = fLSin\theta$

$f = \frac{Wd}{Ltan\theta}$

The maximum friction force would be equivalent to the coefficient of friction by the person, but at the same time to the expression previously found, therefore

$f_{max} = \mu W=\frac{Wd}{Ltan\theta}$

$\theta = tan^{-1} (\frac{d}{\mu L})$

Replacing,

$\theta = tan^{-1} (\frac{0.9}{0.42*2})$

$\theta = 46.975\°$

Therefore the minimum angle that the person can reach is 46.9°

8 0

2 years ago

Under which condition does Ohm's law apply? a. The current must be constant b. The power must be constant c. The temperature mus

ruslelena [56]

Answer:

option c

Explanation:

The temperature must be constant. Ohms law states that the current running through a conductor is directly proportional to the potential difference across it provided the temperature remains constant

6 0

2 years ago

As you can see, my cousin has a lot of hair. He uses an 1800 W blow dryer and it takes him

maw [93]

Power = 1800W (or 1.8KW by dividing by 1000)

Time = 3 hours

Power = energy/ time

1.8KW = energy/ 3

5.4Kw/h= energy

(5.4KJ or 5400J used)

$0.15 Kw/h

$0.15 X 5.4 = 0.81

Thus, cost $0.81

Hope this helps!

5 0

1 year ago