Ask question

Ask question

All categories

4 years ago

6

A suitcase is pulled 28 feet along a flat sidewalk with a constant upward force of 80 lb at an angle of 23degrees with the horiz

ontal. Calculate the work done.

1 answer:

Elenna [48]4 years ago

5 0

Answer:

2795.3 J

Explanation:

distance, d = 28 feet = 8.53 m

Force, F = 80 lb = 356 N

Angle, θ = 23°

Work = F x d x cos θ

W = 356 x 8.53 x cos 23

W = 2795.3 J

Thus, the work done is 2795.3 J.

You might be interested in

7. A pool cue ball moving at 2.1 m/s east collides in a straight line with the eight ball at rest. Find the velocity of the eigh

MArishka [77]

I think the answer is C the cue ball con....

6 0

3 years ago

Read 2 more answers

Germanium to which 1024 m-3 Ga atoms have been added is an extrinsic semiconductor at room temperature, and virtually all the Ga

Svetlanka [38]

Answer:

Electrical Conductivity is 3200 $(\Omega m)^{-1}$

Solution:

As per the question:

$N_{A} = 10^{24}\ m^{- 3}\ Ga\ atoms$

Mobility of electrons, $\mu_{e} = 0.26\ m^{2}/ Vs$

Mobility of holes, $\mu_{h} = 0.020\ m^{2}/ Vs$

Charge, Q = $1.6\times 10^{- 19}\ C$

Now,

The formula for the conductivity is given by:

$\sigma = N_{A}Q\mu_{h}$

$\sigma = 10^{24}\times 1.6\times 10^{- 19}\times 0.020} = 3200(\Omega m)^{-1}$

5 0

3 years ago

Which is a substance that takes the shape and volume of its container?

Gnom [1K]

Which is a substance that takes the shape and volume of its container?

liquid

7 0

3 years ago

An astronaut named Speedo takes a trip to Sirius, which is located a distance of 8 lightyears from the Earth. If the spaceship m

Softa [21]

Answer:

<em>a. 10 years</em>

<em>b. 6 years</em>

<em>c. 12 years behind</em>

<em></em>

Explanation:

speed of light c = 3x $10^{8}$ m/s

distance of sirius from earth = 8 lightyears = 8 x c x 60 x 60 x 24 x 365 = 252288000c meters

speed of spaceship = 0.8c

time taken to reach sirius = distance covered divided by speed

t = d/s = 252288000c/0.8c = 315360000 sec

<em>1 year = 60 x 60 x 24 x 365 sec = 31536000 sec</em>

315360000 sec = 315360000/31536000 = <em>10 yrs</em>

<em>the time as observed by Goslo will be shorter than the real time as measured within the ship due to relativistic effects. using the relativistic relation for time dilation we have</em>

t' = t $\sqrt{1 - \frac{v^{2} }{c^{2} } }$

since v = 0.8c

v/c = 0.8

where t' is the relativistic time as observed by Goslo,

t is the time within the ship

t' = 10 x $\sqrt{1 - 0.8^{2} }$ = <em>6 yrs</em>

<em></em>

If speedo turns around immediately after reaching sirius, his total distance will be 252288000c x 2 = 50457600c meter

time taken = 50457600c/0.8 = 630720000 sec = 20 yrs

time within the ship will be calculated from time dilation

t' = t $\sqrt{1 - \frac{v^{2} }{c^{2} } }$

t' = 20 x $\sqrt{1 - 0.8^{2} }$ = 378432000 sec = <em>12 years behind</em>

4 0

3 years ago

One end of a string 6.26 m long is moved up and down with simple harmonic motion at a frequency of 95 Hz . The waves reach the o

uranmaximum [27]

Answer:

Explanation:

Given

length of string $L=6.26\ m$

frequency $f=95\ Hz$

time taken by wave to reach at other end $t=0.5\ s$

speed of wave is given by

$v=\frac{length\ of\ string}{time\ taken}$

$v=\frac{6.26}{0.5}$

$v=12.52\ m/s$

wavelength of is given by

$\lambda =\frac{velocity}{frequency}$

$\lambda =\frac{12.52}{95}$

$\lambda =0.131\ m$

4 0

3 years ago