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Paladinen [302]
3 years ago
14

. A child drops a ball from a window. The ball strikes the ground in 3.0 seconds. What is the. A child drops a ball from a windo

w. The ball strikes the ground in 3.0 seconds. What is the
velocity of the ball the instant before it hits the ground?
Physics
1 answer:
Vsevolod [243]3 years ago
3 0

Answer:

30m/s

Explanation:

  • Use formula for height calculation: Time = √2h/√g
  • From here calculate height which comes out to be: 45m(if g is taken 10)
  • Then use formula for velocity calculation: v = √2gh

  • The velocity comes out to be 30m/s

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At which point does the planet have the least gravitational force acting on it?
Elza [17]

Answer:

At which point does the planet have the least gravitational force acting on it?

Explanation:

In an elliptical orbit, when a planet is at its furthest point from the Sun, it is under the least amount of gravity, meaning that the force of gravity is strongest when it is closest.

5 0
2 years ago
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003 (part 1 of 2) 10.0 points
drek231 [11]
Theists. You’re welcome
4 0
3 years ago
g Calculate the maximum wavelength of light that will cause the photoelectric effect for potassium. Potassium has work function
Ivahew [28]

Answer:

λ = 5.4196 10⁻⁷m,  λ = 541.96 nm    this is green ligh

Explanation:

The photoelectric effect was explained by Eintein assuming that the light was made up of particles called photons and these collided with the electrons taking them out of the material.

 

                     K = h f -Ф

where K is the kinetic energy of the ejected electrons, hf is the energy of the light quanta and fi is the work function of the material.

The speed of light is related to wavelength and frequency

                   c = λ / f

                  f = c /λ

we substitute

                K = h c / λ - Φ

for the case that they ask us the kinetic energy of the electons is zero (K = 0)

                 h c / λ = Ф

                λ = h c / Ф

we calculate

                 λ = 6.63 10⁻³⁴  3 10⁸ / 3.67 10⁻¹⁸

                 λ = 5.4196 10⁻⁷m

let's take nm

                lam = 541.96 nm

this is green light

4 0
3 years ago
a water bomber flying with a horizontal speed of 85m/s at a height of 3000m drops a load on a fire below. How far in front of th
Andreyy89

Answer:

2081.65 m

Explanation:

We'll begin by calculating the time taken for the load to get to the target. This can be obtained as follow:

Height (h) = 3000 m

Acceleration due to gravity (g) = 10 m/s²

Time (t) =?

h = ½gt²

3000 = ½ × 10 × t²

3000 = 5 × t²

Divide both side by 5

t² = 3000 / 5

t² = 600

Take the square root of both side

t = √600

t = 24.49 s

Finally, we shall determine the distance from the target at which the load should be released. This can be obtained as follow:

Horizontal velocity (u) = 85 m/s

Time (t) = 24.49 s

Horizontal distance (s) =?

s = ut

s = 85 × 24.49

s = 2081.65 m

Thus, the load should be released from 2081.65 m.

3 0
3 years ago
Protons in an atomic nucleus are typically 10−15 m apart. what is the electric force (in n) of repulsion between nuclear protons
dybincka [34]
<span>The electric force is given by: 
 F = [ k*(q1)*(q2) ] / d^2 
 F = Electric force 
 k = Coulomb's constant 
 q1 = Charge of one proton 
 q2 = Charge of second proton 
 d = Distance between centers of mass 
 Values: 
 F = unknown 
 k = 8.98E 9 N-m^2/C^2 
 q1 = 1.6E-19 
 q2 = 1.6E-19 
 d = 1.0E-15 m 
 Insert values into F = [ k*(q1)*(q2) ] / d^2 
 F = [ (8.98E 9 N-m^2/C^2) * (1.6E-19) * (1.6E-19) ] / (1.0E-15 m)^2 
 F = </span>229.888 N
 answer
 the electric force of repulsion between nuclear protons is 229.888 N

3 0
2 years ago
Read 2 more answers
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