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3 years ago

1.

Physics

1 answer:

mojhsa [17]3 years ago

7 0

Answer:

How do you find the average speed in physics?

Average speed is calculated by dividing distance by time (e.g. miles/hour

Explanation:

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In a parallel circuit the component with the highest resistance will have a low electric current.

statuscvo [17]

Should be true.

it's been awhile since I was learning this

4 0

3 years ago

Including them, the mass of the balloon was 1890 kg and had a volume of 11,430 m3 . The balloon floats at a constant height of 6

Monica [59]

Given :

The mass of the balloon was 1890 kg and had a volume of 11,430 m3 .

The balloon floats at a constant height of 6.25m above the ground.

To Find :

The density of the hot air in the balloon.

Solution :

We know,

Volume × ( Density of surrounding air - Density of hot air ) = mass

Putting given values in above equation, we get :

$11430\times ( 1.29 - \rho_{hot \ air } ) = 1890\\\\\rho_{hot \ air } = 1.29 - \dfrac{1890}{11430}\\\\\rho_{hot \ air } = 1.125\ kg\ m^3$

Therefore, the density of hot air in the balloon is 1.125 kg m³.

4 0

3 years ago

9. A car driver brakes gently. Her car slows down front --

sleet_krkn [62]

Answer:

9) This is a case of deceleration

10)-0.8 ms-2

b) acceleration is the change in velocity with time

11)

a) 100 ms-1

b) 100 seconds

12) 10ms-1

13) more information is needed to answer the question

14) - 0.4 ms^-2

15) 0.8 ms^-2

Explanation:

The deceleration is;

v-u/t

v= final velocity

u= initial velocity

t= time taken

20-60/50 =- 40/50= -0.8 ms-2

11)

Since it starts from rest, u=0 hence

v= u + at

v= 10 ×10

v= 100 ms-1

v= u + at but u=0

1000 = 10 t

t= 1000/10

t= 100 seconds

12) since the sprinter must have started from rest, u= 0

v= u + at

v= 5 × 2

v= 10ms-1

14)

v- u/t

10 - 20/ 25

10/25

=- 0.4 ms^-2

15)

a=v-u/t

From rest, u=0

8 - 0/10

a= 8/10

a= 0.8 ms^-2

7 0

4 years ago

Unless indicated otherwise, assume the speed of sound in air to be v = 344 m/s. You have a stopped pipe of adjustable length clo

faltersainse [42]

Answer:

Length of pipe $= 0.057$ meter

Explanation:

Speed of a transverse wave on a string

$v = \sqrt{\frac{F}{\mu} }$

where F is the tension in string and $\mu$ is the mass per unit length

Thus,

$\mu = \frac{m}{L}$

Substituting the given values we get -

$\mu = \frac{7.25 * 10^{-3}}{0.62}\\mu = 0.0117 \frac{Kg}{m}$

Speed of a transverse wave on a string

$v = \sqrt{\frac{4510}{0.0117} } \\v = 620.86 \frac{m}{s}$

For third harmonic wave , frequency is equal to

$f = \frac{nv}{2L}$

Substituting the given values, we get -

$f = \frac{3 * 620.86}{2 * 0.62} \\f = 1502.08$

Length of pipe

$L = \frac{nv}{4 f}$

Substituting the given values we get

$n = 1$ for first harmonic wave

$L = \frac{344* 1}{4*1502.08} \\L = 0.057$

Length of pipe $= 0.057$ meter

5 0

4 years ago

. Using your knowledge of circular (centripetal) motion, derive an equation for the radius r of the circular path that electrons

Ronch [10]

Answer:

Explanation:

Magnetic field creates a force perpendicular to a moving charge in its field which is equal to Bev where B is magnetic field , e is amount of charge on the moving charge and v is the velocity of charge particle .

This force provides centripetal force for creation of circular motion. If r be the radius of the circular path

Bev = mv² / r

r = mv / Be

2 ) If an electron is accelerated by an electric field created by potential difference V then electric field

= V / d where d is distance between two points having potential difference v .

force on charged particle

electric field x charge

= V /d x e

work done by field

= force x distance

= V /d x e x d

V e

This is equal to kinetic energy created

V e = 1/2 mv²

= 1/2 m (r²B²e² / m² )

V = r²B²e/ 2 m

e / m = 2 V/ r²B²

3 )

B = $\frac{\mu\times I\times R^2}{2(R^2+Z^2)^\frac{3}{2} }$

In Helmholtz coils , distance between coil is equal to R so Z = R/2

B = $\frac{\mu\times I\times R^2}{2(R^2+\frac{R^2}{4} )^\frac{3}{2} }$

For N turns of coil and total field due to two coils

B = $\frac{\mu\times I\times N}{R\times(\frac{5}{4})^\frac{3}{2} }$

= $\frac{\mu\times I\times N}{R}\times (\frac{4}{5})^\frac{3}{2}$

= 9.0 x 10^-7 NI/R

8 0

4 years ago