The answer is Infrared. The infrared of the electromagnetic spectrum is most of earth's outgoing terrestrial radiation. <span>Earth is the hot body with temperature of 30 degrees on the average.</span>

6 0

3 years ago

A projectile is fired with initial speed vo at an angle of 45o above the horizontal. Assume no air resistance.

katrin2010 [14]

Answer:

The correct answer is a

Explanation:

At projectile launch speeds are

X axis vₓ = v₀ = cte

Y axis $v_{y}$ = v_{oy} –gt

The moment is defined as

p = mv

For the x axis

pₓ = mvₓ = m v₀ₓ

As the speed is constant the moment is constant

For the y axis

p_{y} = m v_{y} = m (v_{oy} –gt) = m v_{oy} - m (gt)

Speed changes over time, so the moment also changes over time

Let's examine the answer

i True

ii False. The moment changes with time

The correct answer is a

7 0

3 years ago

3. The center of mass (or center of gravity) of a two-particle system is at the origin. One particle

nika2105 [10]

Answer:

B) (-2.0 m, 0.0 m)

Explanation:

Given:

Mass of particle 1 is, $m_1=2.0\ kg$

Mass of particle 2 is, $m_2=3.0\ kg$

Position of center of mass is, $(x_{cm},y_{cm})=(0,0)$

Position of particle 1 is, $(x_1,y_1)=(3.0\ m,0.0\ m)$

Position of particle 2 is, $(x_2,y_2)=(?\ m,?\ m)$

We know that, the x-coordinate of center of mass of two particles is given as:

$x_{cm}=\frac{m_1x_1+m_2x_2}{m_1+m_2}$

Plug in the values given.

$0=\frac{(2.0\times 3)+(3.0\times x_2)}{2.0+3.0}\\\\0=6+3x_2\\\\3x_2=-6\\\\x_2=\frac{-6}{3}=-2.0\ m$

We know that, the y-coordinate of center of mass of two particles is given as:

$y_{cm}=\frac{m_1y_1+m_2y_2}{m_1+m_2}$

Plug in the values given.

$0=\frac{(2.0\times 0)+(3.0\times y_2)}{2.0+3.0}\\\\0=0+3y_2\\\\3y_2=0\\\\y_2=\frac{0}{3}=0.0\ m$

Therefore, the position of particle 2 of mass 3.0 kg is (-2.0 m, 0.0 m).

So, option (B) is correct.

8 0

2 years ago