1. What is evaporation and how does it affect weather?

Swings are usually made out of materials that do not conduct heat easily, so that children will not burn themselves as they play

Irina18 [472]

the correct answer is D: all of these

8 0

3 years ago

An above ground swimming pool of 30 ft diameter and 5 ft depth is to be filled from a garden hose (smooth interior) of length 10

STALIN [3.7K]

This question involves the concepts of dynamic pressure, volume flow rate, and flow speed.

It will take "5.1 hours" to fill the pool.

First, we will use the formula for the dynamic pressure to find out the flow speed of water:

$P=\frac{1}{2}\rho v^2\\\\v=\sqrt{\frac{2P}{\rho}}$

where,

v = flow speed = ?

P = Dynamic Pressure = 55 psi $(\frac{6894.76\ Pa}{1\ psi})$ = 379212 Pa

$\rho$ = density of water = 1000 kg/m³

Therefore,

$v=\sqrt{\frac{2(379212\ Pa)}{1000\ kg/m^3}}$

v = 27.54 m/s

Now, we will use the formula for volume flow rate of water coming from the hose to find out the time taken by the pool to be filled:

$\frac{V}{t} = Av\\\\t =\frac{V}{Av}$

where,

t = time to fill the pool = ?

A = Area of the mouth of hose = $\frac{\pi (0.015875\ m)^2}{4}$ = 1.98 x 10⁻⁴ m²

V = Volume of the pool = (Area of pool)(depth of pool) = A(1.524 m)

V = $[\frac{\pi (9.144\ m)^2}{4}][1.524\ m]$ = 100.1 m³

Therefore,

$t = \frac{(100.1\ m^3)}{(1.98\ x\ 10^{-4}\ m^2)(27.54\ m/s)}\\\\$

<u>t = 18353.5 s = 305.9 min = 5.1 hours</u>

Learn more about dynamic pressure here:

brainly.com/question/13155610?referrer=searchResults

7 0

3 years ago

A piano string having a mass per unit length equal to 5.20 10-3 kg/m is under a tension of 1 450 N. Find the speed with which a

DedPeter [7]

Answer:

The wave in the string travels with a speed of 528.1 m/s

Explanation:

Wave speed of sound waves in a string, v, is related to the Tension in the string, T, and the mass per unit length, μ, by the relation,

v = √(T/μ)

μ = 5.20 × 10⁻³ kg/m

T = 1450N

v = √(1450/0.0052) = 528.1 m/s

Hope this Helps!!!

6 0

3 years ago

1. A SUV along with 5 passengers has a mass of 3500 kg. It has a driving force of 2500 N directed along west on a perfectly hori

Dovator [93]

Answer:

The net acceleration of the SUV is 0.429 meters per square second due west.

Explanation:

Statement is incomplete. Description is presented below:

<em>A SUV along with 5 passengers has a mass of 3500 kg. It has a driving force of 2500 N directed along west on a perfectly horizontal road. The surface of the road exerts a resistance force of 500 N due east. At the same time a high wind is blowing a force of 500 N due east in the opposite direction of the car's drive force. Does the car has any acceleration? If yes, then what are the magnitude and direction of the car's acceleration?</em>

According to Newton's Laws of Motion, the SUV will accelerate if and only if net acceleration is different of zero. Let suppose as positive the direction of driving force ( $F$ ), measured in newtons:

$\Sigma F = F - R -f = F_{net}$ (1)

Where:

$R$ - Resistance force, measured in newtons.

$f$ - Wind force, measured in newtons.

$F_{net}$ - SUV net force, measured in newtons.

If we know that $F = 2500\,N$ , $R = 500\,N$ and $f = 500\,N$ , then net force experimented by the SUV is:

$F_{net} = 2500\,N-500\,N-500\,N$

$F_{net} = 1500\,N$

The car has acceleration.

By definition of force for systems with constant mass, we calculate the acceleration of the vehicle below:

$a_{net} = \frac{F_{net}}{m}$ (2)

Where $m$ is the mass of the SUV, measured in kilograms.

If we know that $F_{net} = 1500\,N$ and $m = 3500\,kg$ , then the net acceleration of the car is:

$a_{net} = \frac{1500\,N}{3500\,kg}$

$a_{net} = 0.429\,\frac{m}{s^{2}}$

The net acceleration of the SUV is 0.429 meters per square second due west.

8 0

3 years ago

Please help! A net force of 2.0 N acts on a 2.0-kg object for 10 seconds. What is the object’s kinetic energy after that 10 seco

padilas [110]

For Newton's second law, the force F applied to the object of mass m will cause an acceleration a of the body:
$F=ma$
So, the acceleration is
$a= \frac{F}{m}= \frac{2.0 N}{2.0 kg}=1 m/s^2$

The object undergoes through this acceleration for 10 seconds, t=10 s. Since it is an accelerated motion, we can find its final velocity after 10 seconds:
$v_f = v_i + at=0 m/s+(1m/s^2)(10 s)=10 m/s$
where $v_i$ is the initial velocity of the object, which is zero since it starts from rest.

Finally we can calculate the final kinetic energy of the object, which is given by
$K= \frac{1}{2}mv^2= \frac{1}{2}(2.0 kg)(10 m/s)^2=100 J$

7 0

3 years ago