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2 years ago

How long does it take light ray B to reach the girls eye? (speed of light at 3*10^8) And could someone explain why?

Physics

1 answer:

kodGreya [7K]2 years ago

6 0

Explanation:

Using properties of 30-60-90 triangles, the distance from the vase to the mirror is 2/√3, and the distance from the mirror to the girl is also 2/√3. So the light travels a total distance of 4/√3 meters.

t = d / v

t = (4/√3 m) / (3×10⁸ m/s)

t = 7.7×10⁻⁹ s

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Needing help with this please

Gemiola [76]

Answer:

So A we cant sadly do because we cant draw. B is going to be kinetic. Thats because static friction means it stays in one place, for kinetic it means moving. So it will be 0.05 as the coefficient of the friction. Sadly, I cannot calculate C. You will have to use trigonemetry but I cannot fit that big an explanation.

Answer to A: the free body diagram would be the ski things inclined with gravity, friction, and air resistance. I except you know which directions

Answer to B: Kinetic friction is the answer.

Answer to C: Find on own, I cannot write super big explanations - use trigonometry.

6 0

3 years ago

A 0.37-kg object connected to a light spring with a force constant of 23.2 N/m oscillates on a frictionless horizontal surface.

mars1129 [50]

Answer:

a) v = 31.67 cm / s , b) v = -29.36 cm / s , c) v= 29.36 cm/s, d) x = 3.46 cm

Explanation:

The angular velocity in a simple harmonic movement is

w = √ K / m

w = √ 23.2 / 0.37

w = 7,918 rad / s

a) the expression against the movement is

x = A cos (wt + Ф)

Speed is

v = dx / dt = - A w sin (wt + Ф)

The maximum speed occurs for cos = ± 1

v = A w

v = 4.0 7,918

v = 31.67 cm / s

b) as the object is released from rest

0 = -A w sin (0+ Фi)

sin Ф = 0

Ф = 0

The equation is

x = 4.0 cos (7,918 t)

v = -4.0 7,918 sin (7,918 t)

v = - 31.67 sin (7.918t)

Let's look for the time for a displacement of x = 1.5 cm, remember that the angles must be in radians

7,918 t = cos⁻¹ 1.5 / 4.0

t = 1,186 / 7,918

t = 0.1498 s

We look for speed

v = -31.67 sin (7,918 0.1498)

v = -29.36 cm / s

c) if the object passes the equilibrium equilibrium position again at this point the velocity has the same module, but the opposite sign

v = 29.36 cm / s

d) let's look for the time for the condition v = v_max / 2

31.67 / 2 = 31.67 sin ( 7,918 t)

7.918t = sin⁻¹ 0.5

t = 0.5236 / 7.918

t = 0.06613

With this time let's look for displacement

x = 4.0 cos (7,918 0.06613)

x = 3.46 cm

6 0

3 years ago

A car covers 400 km in an hour towards west .calculate the velocity

crimeas [40]

Answer:

-400km/hr

Explanation:

Velocity=displacement/time

=400/1

=400Km/hr

=-400km/hr (because west direction)

7 0

2 years ago

A rocket will move upward as long as which condition applies?

Dennis_Churaev [7]

The force of thrust is greater than the force if gravity !
Answer found on quizlet !

8 0

3 years ago

An early method of measuring the speed of light makes use of a rotating slotted wheel. A beam of light passes through one of the

Readme [11.4K]

Answer:

4.7 x 10³ rad / s

Explanation:

During the time light goes and comes back , one slot is replaced by next slot while rotating before the light source

Time taken by light to travel a distance of 2 x 500 m is

= (2 x 500) / 3 x 10⁸

= 3.333 x 10⁻⁶ s .

In this time period, two consecutive slots come before the source of light one after another by rotation. There are 400 slots so time taken to make one rotation

= 3.333 x 10⁻⁶ x 400

= 13.33 x 10⁻⁴ s

This is the time period so

T = 13.33 X 10⁻⁴

Angular speed

= 2π / T

= $\frac{2\times3.14}{13.33\times10^{-4}}$

4.7 x 10³ rad / s

5 0

2 years ago