All categories

2 years ago

A man holding 7N weight moves 7m horizontal and 5m vertical , find the work done

Physics

1 answer:

SashulF [63]2 years ago

8 0

Answer:

35 J

Explanation:

The man is holding the box: this means that he is applying a force vertically upward, to balance the weight of the box (which pushes downward).

Therefore, we can ignore the horizontal displacement of the man, because the force applied (vertically upward) is perpendicular to that displacement (horizontal), so the work done for that is zero.

So, only the vertical motion contributes to the work. The work done by the man is equal to the gain in gravitational potential energy of the box, so:

$W=(mg)\Delta h$

where

$mg=7 N$ is the weight of the box

$\Delta h=5 m$ is the vertical displacement

Substituting, we find

$W=(7N)(5 m)=35 J$

You might be interested in

A signal generator has an output voltage of 2.0 V with no load. When a 600 Ω load is connected to it, the output drops to 1.0 V.

kicyunya [14]

Answer:

600 Ω

Explanation:

when there is no load attached to the generator the circuit is open and zero current flows through the circuit, hence voltage drop across the internal resister is zero.

when 600Ω load is connected current starts flowing through the circuit and some voltage will drop across the internal resister.

voltage across the load resister is 1 V, so the current through it will be:

I=V/R

I=1/600 A= 1.67mA

voltage drop in the internal resister is:

V= input voltage - output voltage

V=2 V-1 V

⇒V=1 V

Now by using ohm's law

R=V/ I

R= $\frac{1}{1.67*10^{-3} }$ (I= 1.67mA, as the resistors are connected in series)

⇒R=600 Ω

Hence Thevinin resistance of the generator is 600Ω.

5 0

1 year ago

A beam of unpolarized light shines on a stack of five ideal polarizers, set up so that the angles between the polarization axes

ddd [48]

Answer:

$21.75$

Explanation:

$n$ = number of polarizers through which light pass through = 5

$\theta$ = Angle between each pair of adjacent polarizers

$I_{o}$ = Intensity of unpolarized light

$I_{n}$ = Intensity of transmitted beam after passing all polarizers

It is given that

$\frac{I_{n}}{I_{o}}= 0.277$

we know that the intensity of light after passing through "n" polarizers is given as

$I_{n} = (0.5) I_{o} Cos^{2n-2}\theta$

$\frac{I_{n}}{I_{o}} = (0.5) Cos^{2n-2}\theta$

inserting the values

$0.277 = (0.5)Cos^{2(5)-2}\theta$

$0.554 = Cos^{8}\theta$

$Cos\theta = 0.9288$

$\theta = Cos^{-1}(0.9288)$

$\theta = 21.75$

7 0

1 year ago

A "biconvex" lens is one in which both surfaces of the lens bulge outwards. Suppose you had a biconvex lens with radii of curvat

Stolb23 [73]

Answer: f=150cm in water and f=60cm in air.

Explanation: Focal length is a measurement of how strong light is converged or diverged by a system. To find the variable, it can be used the formula:

$\frac{1}{f}$ = (nglass - ni)( $\frac{1}{R1}$ - $\frac{1}{R2}$ ).

nglass is the index of refraction of the glass;

ni is the index of refraction of the medium you want, water in this case;

R1 is the curvature through which light enters the lens;

R2 is the curvature of the surface which it exits the lens;

Substituting and calculating for water (nwater = 1.3):

$\frac{1}{f}$ = (1.5 - 1.3)( $\frac{1}{10}$ - $\frac{1}{15}$ )

$\frac{1}{f}$ = 0.2( $\frac{1}{30}$ )

f = $\frac{30}{0.2}$ = 150

For air (nair = 1):

$\frac{1}{f}$ = (1.5 - 1)( $\frac{1}{10}$ - $\frac{1}{15}$ )

f = $\frac{30}{0.5}$ = 60

In water, the focal length of the lens is f = 150cm.

In air, f = 60cm.

5 0

2 years ago

Read 2 more answers

Paula is studying two different animals. Both animals are classified within the same genus, but they are different species. Base

Ksivusya [100]

Answer:c

Explanation:

i think

6 0

1 year ago

Read 2 more answers

Follow these steps to solve this problem: Two identical loudspeakers, speaker 1 and speaker 2, are 2.0 m apart and are emitting

horsena [70]

Answer:

Explanation:

Wave length of sound from each of the speakers = 340 / 1700 = .2 m = 20 cm

Distance between first speaker and the given point = 4 m.

Distance between second speaker and the given sound

= √ 4² + 2² = √16 +4 = √20 = 4.472 m

Path difference = 4.472 - 4 = .4722 m.

Path difference / wave length = 0.4772 / 0.2 = 2.386

This is a fractional integer which is neither an odd nor an even multiple of half wavelength. Hence this point of neither a perfect constructive nor a perfect destructive interference.

7 0

1 year ago