Fill in the appropriate word or term for the following statements.

Shiny reflective clothing allows a firefighter to get closer to a fire. What type of heat transfer is reduced because of this ma

joja [24]

A.) conduction.

conduction is the process by which heat or electricity is directly transmitted through a substance when there is a difference of temperature or of electrical potential between adjoining regions, without movement of the material.

6 0

3 years ago

A military helicopter on a training mission is flying horizontally at a speed of 90.0 m/s when it accidentally drops a bomb (for

Elena-2011 [213]

Answer:

1) 10.1 s 2) 909 m 3) 90.0 m/s 4) -99m/s 5) just over the bomb.

Explanation:

1)

In the vertical direction, as the bomb is dropped, its initial velocity is 0.
So, we can find the time required for the bomb to reach the earth, applying the following kinematic equation for displacement:

$\Delta y = \frac{1}{2}*a*t^{2} (1)$

where Δy = -500 m (taking the upward direction as positive).
a=-g=-9.8 m/s²
Replacing these values in (1), and solving for t, we have:

$t =\sqrt{\frac{2*\Delta y}{-g}} = \sqrt{\frac{2*(-500m)}{-9.8m/s2}} = 10.1 s$

The time required for the bomb to reach the earth is 10.1 s.

2)

In the horizontal direction, once released from the helicopter, no external influence acts on the bomb, so it will continue moving forward at the same speed. that it had, equal to the helicopter.
As the time must be the same for both movements, we can find the horizontal displacement just as the product of this speed times the time, as follows:

$x = v_{0x} * t = 90.0 m/s * 10.1 s = 909 m.$

3)

The horizontal component of the bomb's velocity is the same that it had when left the helicopter. i.e. 90 m/s.

4)

In order to find the vertical component of the bomb's velocity just before it strikes the earth, we can apply the definition of acceleration, remembering that v₀ = 0, as follows:

$v_{f} = -g*t = -9.8 m/s2*10.1 s = -99 m/s$

5)

If the helicopter keeps flying horizontally at the same speed, it will be always over the bomb, as both travel horizontally at the same speed.
So, when the bomb hits the ground, the helicopter will be exactly over it.

8 0

4 years ago

A woman lifts a 300 newton child a distance of 1.5 meters in 0.75 seconds. What is her power output in lifting the child?

Nitella [24]

Power = Work done / time

Work done = Force * Distance
= 300 N * 1.5 m = 450 J

Power = 450 / 0.75 = 600 Watts.

7 0

3 years ago

In an orbiting space shuttle, you are handed two identical boxes, one filled with sand and the other filled with feathers. How c

Aleks04 [339]

Explanation:

Simply, shake the boxes. The box that is difficult to shake will be the sand and the box that will be easier will be the feathers.

3 0

4 years ago

I need help with these questions :<br>(see image )

maw [93]

<h2>Hey There!</h2><h2>_____________________________________</h2><h2>Answer:</h2>

$\huge\boxed{Theta=25.67}$

Range = R = 78m

Initial Velocity = $V_i$ = 30m/s

Angle(theta) = ?

<h2>_____________________________________</h2><h3>SOLUTION:</h3>

The Range is given by,

$R =\frac{V_0^2}{g}Sin2(theta)\\\\78 = \frac{30^2}{10}Sin2(theta)\\\\Sin2(theta) = \frac{780}{900}\\\\Sin2(theta) = \frac{13}{15}\\\\Sin(theta) = \frac{13}{30}\\\\theta = Sin^{-1}\frac{13}{30}\\\\theta = 25.67^0$

<h2>_____________________________________</h2><h2>Best Regards,</h2><h2>'Borz'</h2><h2 />

7 0

3 years ago