I need help i don’t understand

rt A For a given substance, do you expect the density of the substance in its liquid state to be closer to the density in the ga

Nat2105 [25]

Answer:

A substance in its liquid state is closer to the density of its solid phase than the density of its gaseous phase.

Explanation:

For a substance in its liquid state we can expect the density of the substance more closer to the density of its solid state than its gaseous state because the the inter-molecular space is much close near to incompressible in the liquid state and the the inter-molecular force of attraction is much higher as compared to gaseous state.

In contrast to the molecular properties in liquid state gases have almost negligible inter-molecular force of attraction and very huge inter-molecular spacing which makes it well compressible.

8 0

3 years ago

How to find initial velocity in projectile motion problems when you are not given the vlocity?

Papessa [141]

Vi= square root vi^2 -2ad

7 0

4 years ago

A plane drops a rubber raft to the survivors of a shipwreck. The plane is flying at a height of 1960 m and with a speed of 109 m

Korolek [52]

In this case the rubber raft has horizontal and vertical motion.

Considering vertical motion first.

We have displacement $s = ut +\frac{1}{2}at^2$ , u = Initial velocity, t = time taken, a = acceleration.

In vertical motion

s = 1960 m, u = 0 m/s, a = 9.81 $m/s^2$

$1960 = 0*t+\frac{1}{2} *9.81*t^2\\ \\ t = 20 seconds$

So raft will take 20 seconds to reach ground.

Now considering horizontal motion of raft

u = 109 m/s, t = 20 s, a = 0 $m/s^2$

So $s = 109*20+\frac{1}{2} *0*20^2 = 2180 m$

So shipwreck was 2180 meter far away from the plane when the raft was dropped.

8 0

3 years ago

The Falcon 9 rocket has a mass of 549,000 kg and in 70 seconds into the launch, the rocket reaches a speed of 343.2 m/s. What is

yaroslaw [1]

Explanation:

=5.49*10^5*343.2

=1.8846*10^8

8 0

3 years ago

Suppose your surface body temperature averaged 90 degrees F. How much radiant energy in W/m^2 would be emitted from your body?

Debora [2.8K]

$493 \; \text{W}\cdot \text{m}^{-2}$ .

<h3>Explanation</h3>

The Stefan-Boltzmann Law gives the energy radiation <em>per unit area</em> of a black body:

$\dfrac{P}{A} = \sigma \cdot T^{4}$

where,

$P$ the total power emitted,
$A$ the surface area of the body,
$\sigma$ the Stefan-Boltzmann Constant, and
$T$ the temperature of the body in degrees Kelvins.

$\sigma = 5.67 \times 10^{-8} \;\text{W}\cdot \text{m}^{-2} \cdot \text{K}^{-4}$ .

$T = 90 \; \textdegree{}\text{F} = (\dfrac{5}{9} \cdot (90-32) + 273.15) \; \text{K} = 305.372 \; \text{K}$ .

$\dfrac{P}{A} = \sigma \cdot T^{4} = 5.67 \times 10^{-8} \times 305.372^{4} = 493\; \text{W}\cdot \text{m}^{-2}$ .

Keep as many significant figures in $T$ as possible. The error will be large when $T$ is raised to the power of four. Also, the real value will be much smaller than $493\; \text{W}\cdot \text{m}^{-2}$ since the emittance of a human body is much smaller than assumed.

5 0

3 years ago