A uniform-density sphere whose mass is 13 kg and radius is 0.3 m

Light with a wavelength of 395 nm illuminates a metal cathode. The maximum kinetic energy of the emitted electrons is 0.76 eV .

lutik1710 [3]

Answer:

520.8 nm

Explanation:

We are given that

$\lambda=395 nm=395\times 10^{-9} m$

1 nm= $10^{-9} m$

Maximum kinetic energy, $K_{max}=0.76 eV=0.76\times 1.6\times 10^{-19}$ V

$1 e=1.6\times 10^{-19} C$

We have to find the maximum wavelength of light.

We know that

$h\nu=\frac{hc}{\lambda_0}+K_{max}$

Where $c=3\times 10^8 m/s$

$h=6.625\times 10^{-34}$

$6.625\times 10^{-34}\times \frac{3\times 10^8}{395\times 10^{-9}}=\frac{6.625\times 10^{-34}\times 3\times 10^8}{\lambda_0}+0.76\times 1.6\times10^{-19}$

$6.625\times 10^{-34}\times \frac{3\times 10^8}{395\times 10^{-9}}- 0.76\times 1.6\times10^{-19}=\frac{6.625\times 10^{-34}\times 3\times 10^8}{\lambda_0}$

$\lambda_0=\frac{6.625\times 10^{-34}\times 3\times 10^8}{6.625\times 10^{-34}\times \frac{3\times 10^8}{395\times 10^{-9}}- 0.76\times 1.6\times10^{-19}}$

$\lambda_0=5.208\times 10^{-7} m$ =520.8 nm

6 0

3 years ago

The mass of the Earth is 5.98 × 1024 kg . A 11 kg bowling ball initially at rest is dropped from a height of 2.63 m. The acceler

jekas [21]

Answer:

v = 7.18_m/s

Explanation:

Velocity of the earth towards the ball is = velocity of the ball moving towards earth

For object in free fall, we have

Where

v = final velocity

u = initial velocity

g = acceleration due to gravity

t = time

S = height of ball above ground

v^2 = u^2 - 2×g×(-S)

= 0 + 2×9.8×2.63 = 51.55_m^2/s^2

Velocity of the ball just before it hits the ground is

v = 7.18_m/s

3 0

3 years ago

A circuit is built based on the circuit diagram shown.

goldfiish [28.3K]

I think the answer is B

4 0

3 years ago

Which of the following best describes a plane?

ASHA 777 [7]

From that list of choices, choice 'B' is the only example of a plane,
but it doesn't 'describe' it at all.

7 0

3 years ago

(a) You wish to determine the height of the smokestack of a local coal burning power plant. You convince a member of the mainten

kicyunya [14]

Answer:

a. 86.80 m

b. i. The mass of the bob

ii. The length of the pendulum

Explanation:

a. Determine the height of the smokestack.

Using T = 2π√(L/g) where T = period of pendulum = 18.7 s, L = length of pendulum = height of smokestack and g = acceleration due to gravity = 9.8 m/s².

So, making L subject of the formula, we have

T = 2π√(L/g)

T/2π = √(L/g)

squaring both sides, we have

(T/2π)² = L/g

L = (T/2π)²g

Substituting the values of the variables into the equation, we have

L = (T/2π)²g

L = (18.7 s/2π)²(9.8 m/s²)

L = (2.976 s)²(9.8 m/s²)

L = 8.857 s² × 9.8 m/s²

L = 86.796 m

L ≅ 86.80 m

b. What factors influence the period of a simple pendulum

The factors that influence the period of a simple pendulum are

i. The mass of the bob

ii. The length of the pendulum

5 0

3 years ago