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3 years ago

A rock is dropped from a cliff and hits the ground 6.0 seconds later. How high is the cliff?

Physics

2 answers:

PolarNik [594]3 years ago

6 0

It all depends on the wight of the rock to but each 1 sec is 1 mile so about 6 miles

Lemur [1.5K]3 years ago

5 0

Answer:

The height of the cliff is found to be 176.4 m

Explanation:

Since, the body is being dropped from a certain height and reaches the ground in some time. Thus, we can apply the equations of motion (modified for vertical motion) in this case, due to constant accelerated motion. We have the following data:

Acceleration due to gravity = g = 9.8 m/s²

Time to reach ground = t = 6 sec

Initial Velocity of the Rock = Vi = 0 m/s (Because, the rock will be at rest, initially)

Height of cliff = H = ?

Now, applying second equation of motion (modified for vertical motion), to the rock, between the top of the cliff and ground, we get:

H = Vi t + (1/2)gt²

Using values:

H = (0 m/s)(6 sec) + (1/2)(9.8 m/s²)(6 sec)²

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A light ray incident on a block of glass makes an incident angle of 50.0° with the normal to the surface. The refracted ray in t

Andru [333]

Answer:

$n_{glass} = 1.65$

Explanation:

As we know that the angle of incidence is given as

$i = 50.0^o$

also we have angle of refraction as

$r = 27.7^o$

now by Snell's law we know that

$n_{air} sin i = n_{glass} sin r$

$1 sin50 = n_{glass} sin 27.7$

now we have

$n_{glass} = \frac{sin 50}{sin 27.7}$

$n_{glass} = 1.65$

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3 years ago

A whale comes to the surface to breathe and then dives at an angle of 20.0 ∘ below the horizontal (see the figure (Figure 1)). I

Bond [772]

Answer:

The question is missing something it doesn't say how fast down its going and doesn't show the figure sorry for wasting an answer

7 0

2 years ago

What is the speed of an 800 kg automobile if it has a kinetic energy of 9.00 x 10^J?

MA_775_DIABLO [31]

Ek = 1/2 mv^2

9 × 10^4 = 1/2 × 800 × v^2

9 × 10^4/400 = 400 v^2 / 400

9 × 10^4/400 = v^2

√225 = v

15 ms⁻¹ = v

That's the only way I know how to work it out

I think in this case velocity and speed would be considered the same because me

s = d/t and v=d/t

one is distance travelled and the other is displacement of a body

7 0

2 years ago

A cook preparing a meal for a group of people is an example of

Fudgin [204]

Kinetic and potential energy he has the ability to make a meal and because he is making the meal

6 0

4 years ago

A 26 kg body is moving through space in the positive direction of an x axis with a speed of 350 m/s when, due to an internal exp

Gnom [1K]

Answer:

a.) 1567.2 m/s

b.) 149.4 m/s

Explanation:

Given that a 26 kg body is moving through space in the positive direction of an x axis with a speed of 350 m/s when, due to an internal explosion, it breaks into three parts. One part, with a mass of 7.8 kg, moves away from the point of explosion with a speed of 180 m/s in the positive y direction. A second part, with a mass of 8.8 kg, moves in the negative x direction with a speed of 640 m/s.

The x-component of the third part can be calculated by assuming that it moves in a positive x axis.

The third mass = 26 - ( 7.8 + 8.8)

The third mass = 26 - 16.6

The third mass = 9.4kg

since momentum is conserved, the momentum before explosion will be equal to sum of the momentum after explosion

26 x 350 = -8.8 x 640 + 9.4V

9100 = -5632 + 9.4V

9.4V = 9100 + 5632

9.4V = 14732

V = 14732/9.4

V = 1567.2 m/s

(b) y-component of the velocity of the third part will be

7.8 x 180 = 9.4 V

1404 = 9.4V

V = 1404/9.4

V = 149.4 m/s

7 0

3 years ago