If a glass rod is rubbed with a dry cloth, what kind of charge would it be:

What frequency is received by a person watching an oncoming ambulance moving at 115 km/h and emitting a steady 753 Hz sound from its siren? Speed of sound is 345m/s

b. What frequency does she receive after the ambulance has passed?

Vs= speed of the ambulance

, We convert to m/s for unit consistency

= 115 km/h= 115km× 1000m/1m × 1hr/3600s= 31.94m/s

Dopler effect is when observed frequency of wave changes with respect to the source or when observed moves relative to transmitting medium can be expressed as

f'=[ (v + vo)/(v- vs)]*f

=[ (v )/(v- vs)]*f

The sign vo and vs depends on vthe direction of the velocity

f= frequency of ambulance siren= 753Hz

v= speed of sound in air= 345m/s

Vo= speed of observer= 0

A) we are to determine the f' of ambulance as heard by person as ambulance approaching.

To find the frequency f' observed by the person we use the expresion below

Then substitute the values

f'=[ (v )/(v- vs)]*f

=[ (345)/(345-31.94)]×753

= 828.8Hz

B)What frequency does she receive after the ambulance has passed?

To find the frequency f' observed by the person we use the expresion below

Then substitute the values

f'=[ (v )/(v + vs)]*f

=[ (345)/(345 + 31.94)]×753

= 869.2Hz

=

4 0

3 years ago

Health professionals can help those with health issues to __________.

erastovalidia [21]

Answer:

B

Explanation:

8 0

3 years ago

Read 2 more answers

A baseball is hit so that it travels straight upward after being struck by the bat. A fan observes that it takes 3.00 s for the

Vladimir [108]

Answer:

Initial velocity = $29.43m/s$ b) Height it reaches = 44.145 m

Explanation:

Using the first equation of motion we have

$v=u+at$

here

v is the final velocity

u is the initial velocity

a is the acceleration of the object

t is time

When the ball reaches it's highest point it's velocity will become 0 as it will travel no further

Also the acceleration in our case is acceleration due to gravity ( $-9.8m/s^{2}$ ) as the ball moves in it's influence alone with '-' indicating downward direction

Thus applying the values we get

$0=u-(9.81)m/s^{2}\times 3\\\\u=19.43m/s$

b)

By 3rd equation of motion we have

$v^{2}-u^{2}=2gs$

here s is the distance covered

Applying the value of u that we calculated we get

$s=\frac{-u^{2}}{2g}\\\\s=\frac{-29.43^{2}}{-2\times 9.81}\\\\s=44.145m$

7 0

3 years ago