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Identify the two pieces of information you need to know the velocity of an object

Georgia [21]

Manuel with and height?

8 0

3 years ago

SCALCET8 3.9.018.MI. A spotlight on the ground shines on a wall 12 m away. If a man 2 m tall walks from the spotlight toward the

Firlakuza [10]

Answer:

The length of his shadow is decreasing at a rate of 1.13 m/s

Explanation:

The ray of light hitting the ground forms a right angled triangle of height H, which is the height of the building and width, D which is the distance of the tip of the shadow from the building.

Also, the height of the man, h which is parallel to H forms a right-angled triangle of width, L which is the length of the shadow.

By similar triangles,

H/D = h/L

L = hD/H

Also, when the man is 4 m from the building, the length of his shadow is L = D - 4

So, D - 4 = hD/H

H(D - 4) = hD

H = hD/(D - 4)

Since h = 2 m and D = 12 m,

H = 2 m × 12 m/(12 m - 4 m)

H = 24 m²/8 m

H = 3 m

Since L = hD/H

and h and H are constant, differentiating L with respect to time, we have

dL/dt = d(hD/H)/dt

dL/dt = h(dD/dt)/H

Now dD/dt = velocity(speed) of man = -1.7 m/s ( negative since he is moving towards the building in the negative x - direction)

Since h = 2 m and H = 3 m,

dL/dt = h(dD/dt)/H

dL/dt = 2 m(-1.7 m/s)/3 m

dL/dt = -3.4/3 m/s

dL/dt = -1.13 m/s

So, the length of his shadow is decreasing at a rate of 1.13 m/s

5 0

3 years ago

A project is located in an area with a demand-response program and on a site that has enough room for a wind-turbine to allow fo

Ksju [112]

Answer:

A. The project's energy costs will decrease

Explanation:

Since the project is located in an area with a demand-response program and on a site that has enough room for a wind-turbine to allow for on-site renewable energy.

Hence, the project's energy costs will decrease very well because it's implementing both of these strategies;

- Area with demand-response program.

- On-site renewable energy.

5 0

3 years ago

If an electron is accelerated from rest through a potential difference of 9.9 kV, what is its resulting speed

beks73 [17]

Answer:

v = 5.9 x 10⁷ m/s

Explanation:

The kinetic energy of the electron in terms of potential difference is given as:

$K.E = eV$ --------------- equation (1)

where,

e = charge on electron = 1.6 x 10⁻¹⁹ C

V = Potential Difference = 9.9 KV = 9900 Volts

The kinetic energy in general is given as:

$K.E = \frac{1}{2}mv^{2}\\$ --------- equation (2)

where,

m = mass of electron = 9.1 x 10⁻³¹ kg

v = speed of electron = ?

Therefore, comparing equation (1) and equation (2), we get:

$\\\frac{1}{2}mv^{2} = eV\\\\\frac{1}{2}(9.1\ x\ 10^{-31}\ kg)v^{2} = (1.6\ x\ 10^{-19}\ C)(9900\ volts)\\\\v = \sqrt{34.81\ x\ 10^{14}} \\$

8 0

3 years ago

At the circus, the Human Cannonball is

svlad2 [7]

The correct answer is 1.4285714.

In physics, velocity is characterised as a vector measurement of the motion's direction and speed. To be more precise, the rate of change in an object's position relative to a frame of reference and time is another way to describe velocity. The definition of velocity simply states the rate of motion of an object in a specific direction. It determines how quickly or slowly something is going.

Velocity = distance/ time

Thus time = distance/velocity

Here velocity = 350m/s

diatnce = 500 m

time = 500/350

time = 1.42857142857

t= 200m /350m/s = 1.4285714

To learn more about velocity refer the link:

brainly.com/question/18084516

#SPJ9

6 0

1 year ago