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3 years ago

Viruses are different from bacteria in that

Physics

2 answers:

loris [4]3 years ago

7 0

the answer to the question is A.

Marianna [84]3 years ago

7 0

Answer:

Explanation:

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In order for acceleration to occur, something must be..

hoa [83]

Acceleration occurs whenever the direction or the speed changes

8 0

4 years ago

You are trying to overhear a juicy conversation, but from your distance of 20.0 m , it sounds like only an average whisper of 30

12345 [234]

Answer:

r₂ = 0.2 m

Explanation:

given,

distance = 20 m

sound of average whisper = 30 dB

distance moved closer = ?

new frequency = 80 dB

using formula

$\beta = 10 log(\dfrac{I_1}{I_0})$

I₀ = 10⁻¹² W/m²

now,

$30 = 10 log(\dfrac{I_1}{10^{-12}})$

$\dfrac{I_1}{10^{-12}}= 10^3$

$I_1= 10^{-8}\ W/m^2$

to hear the whisper sound = 80 dB

$80 = 10 log(\dfrac{I_2}{10^{-12}})$

$\dfrac{I_2}{10^{-12}}= 10^8$

$I_2= 10^{-4}\ W/m^2$

we know intensity of sound is inversely proportional to square of distances

$\dfrac{I_1}{I_2}=\dfrac{r_2^2}{r_1^2}$

$\dfrac{10^{-8}}{10^{-4}}=\dfrac{r_2^2}{20^2}$

$10^{-4}=\dfrac{r_2^2}{20^2}$

r₂ = 0.2 m

6 0

4 years ago

How do the gravitational potential energy and the kinetic energy of the ball change as the ball rolls down the ramp?

belka [17]

Explanation:

The gravitational potential energy is given by :

P = mgh

The kinetic energy of an object is given by :

$K=\dfrac{1}{2}mv^2$

As the ball reaches the bottom of the ramp, its potential energy decreases and kinetic energy increases.

It imply that, when the ball at the top most height, its gravitational potential energy is maximum and zero kinetic energy and when ball reaches the bottom of the ramp, it will have maximum kinetic energy and zero potential energy.

3 0

3 years ago

A device that transforms electrical energy to mechanical energy is a

yarga [219]

Answer:

Electric Motor

Explanation:

There are mainly two types of machines for inter-conversion between mechanical energy and electrical energy as under:

Motor
Generator

Motor is a device which converts electrical energy into a mechanical whereas generator does the exact opposite of motor.

There are 2 types of motors:

AC Motor - Converts alternating current into mechanical energy

DC Motor - Converts direct current into mechanical energy

4 0

4 years ago

Two precautions in images of a convex lens

yan [13]

Answer:

1 . rays should passs through correct center or points(i.e. optic center or focus)

2.your line representing rays should be straight and u should tell the nature of image

Explanation:

5 0

4 years ago

Read 2 more answers