True of False: All body parts and organs

A 29 cm pencil is placed 35cm in front of a convex lens and is illuminated by a spotlight. the focal point of the lens is 28cm f

vovikov84 [41]

A) What is the height of the pencil image

4 0

2 years ago

What is the frequency of radiation whose wavelength is 11.5 a0 ?

irakobra [83]

Answer:

The frequency of radiation is $2.61 \times 10^{17} s^{-1}$

Explanation:

Given:

Wavelength $\lambda = 11.5 \times 10^{-10}$ m

Speed of light $c = 3 \times 10^{8}$ $\frac{m}{s}$

For finding the frequency of radiation,

$c = f \lambda$

$f = \frac{c}{\lambda}$

$f = \frac{3 \times 10^{8} }{11.5 \times 10^{-10} }$

$f = 2.61 \times 10^{17}$ $s^{-1}$

Therefore, the frequency of radiation is $2.61 \times 10^{17} s^{-1}$

4 0

1 year ago

Given that an electric field of 3×106V/m3×106V/m is required to produce an electrical spark within a volume of air, estimate the

Andre45 [30]

Answer:

Length, l = 33.4 m

Explanation:

Given that,

Electrical field, $E=3\times 10^6\ V/m$

Let the electrical potential is, $V=10^8\ V$

We need to find the length of a thundercloud lightning bolt. The relation between electric field and the electric potential is given by :

$V=E\times d\\\\d=\dfrac{V}{E}\\\\d=\dfrac{10^8}{3\times 10^6}\\\\d=33.4\ m$

So, the length of a thundercloud lightning bolt is 33.4 meters. Hence, this is the required solution.

5 0

2 years ago

Sort these statements about machines based on whether they are correct or incorrect.

insens350 [35]

as well.

1. Correct

Explanation

An inclined plane is a flat surface which lie at an angle, Its one end is higher than the other this inclined plane is used as an aid for raising or lowering a load. Staircase also work in similar manner

2. Correct

Explanation

yes all simple machine have a fulcrum

3. Incorrect

Explanation

when we swim that time our arms and legs 'push' the water due to which water displaced in backward direction so her we applied a positive work on the water. According to Newton's Third Law,same magnitude of work is done by water in opposite direction to push us back on our arms and legs. therefore water also does positive work on us.

4. incorrect

Explanation

The force exerted by a machine on an object is input force

5. Incorrect

Explanation

when the input force is greater than the output force that time machine have mechanical advantage of less than 1.

8 0

1 year ago

Read 2 more answers

Male Rana catesbeiana bullfrogs are known for their loud mating call. The call is emitted not by the frog's mouth but by its ear

Sidana [21]

Answer:

The amplitude of the eardrum's oscillation is 6.65×10^-13 m.

Explanation:

Given data:

The sound has a frequency of 262 Hz

The sound level is 84 dB

The air density is 1.21 kg/m^3

The speed of sound is 346 m/s

Solution:

As, Intensity of sound is given by,

I = Io×10^(s/10 db)

I = 2×π^2×ρ×v×f^2×Sm^2

Thus,

Sm = √(Io×10^(s/10 db)) / √( 2×π^2×ρ×v×f^2)

Now, put the values,

Sm = √( 10^-12 × 10^(84/10) ) / √( 2×(3.14)^2×1.21×346×(262)^2 )

Sm = √(2.51×10^-4 / 5.66×10^8)

Sm = √0.443×10^-12

Sm = 6.65×10^-13 m.

8 0

1 year ago