Calculate the speed of a train that traveled 810 kilometers in 9 hours.

When would a negative value for distance make sense?( think about velocity)

inn [45]

Answer:

An object which moves in the negative direction has a negative velocity. If the object is speeding up then its acceleration vector is directed in the same direction as its motion (in this case, a negative acceleration).

Explanation:

3 0

3 years ago

1. Find an example of electrical energy being converted to light energy.

Svetradugi [14.3K]

Solar energy is the example of electrical energy

6 0

3 years ago

The pressure at the bottom of a cylindrical container with a cross-sectional area of 45.5 cm2 and holding a fluid of density 420

iris [78.8K]

Answer:

3.33 m

Explanation:

Pressure is the distributed force applied to the surface of an object per unit area. The force is applied perpendicular to the surface of the object. The SI unit of pressure is N/m² or Pa.

Hydrostatic pressure is the pressure that a fluid exerts at a point due to the force of gravity.

The relationship between pressure on the bottom of the container, atmospheric pressure and the pressure due to the depth of the fluid is given by:

$P_{bottom}-P_{atm}=P_{depth}\\\\where\ P_{bottom}=pressure\ at\ the \ fluid\ bottom,\ P_{atm}=atmospheric\ pressure\\P_{depth}=pressure\ due\ to\ fluid\ depth=\rho gh. \ Hence:\\\\P_{bottom}-P_{atm}=\rho gh\\\\Given \ that\ P_{bottom}=115\ kPa=115*10^3\ Pa, let\ us\ assume\ P_{atm}=101\ kPa=101*10^3\ Pa,\rho=420\ kg/m^3,g=acceleration\ due\ to \ gravity=10\ m/s^2.\\\\Therefore:\\\\115*10^3-101*10^3=420*10*h\\\\14*10^3=4200h\\\\h=3.33\ m\\\\$

6 0

3 years ago

A balloon is 3m in diameter and is filled with 5 kg of N2. Find the specific volume of the gas in the balloon. Express it in bo

enyata [817]

Answer:

The the specific volume and weight are 79.16m³/k mol and 49 N.

Explanation:

Given that,

Diameter = 3 m

Mass of N₂ = 5 kg

We need to calculate the volume of balloon

Using formula of volume

$V= \dfrac{4}{3}\pi r^3$

$V= \dfrac{4}{3}\pi \times{\dfrac{d}{2}}^3$

$V= \dfrac{4}{3}\pi \times(\dfrac{3}{2})^3$

$V=14.137\ m^3$

We need to calculate the specific volume in the balloon

$Specific\ volume=\dfrac{Volume}{mass}$

$Specific\ volume=\dfrac{14.137}{5}$

$Specific\ volume=2.8274\ m^3/kg$

Now, Molar mass of N₂ gas is 0.028 kg/mol

Now, Specific volume of N₂ gas in the balloon is

$Specific\ volume =0.028\times2.8274=0.0791672\ m^3/mol$

$Specific\ volume =79.16m^3/kmol$

(b). We need to calculate the weight of the gas in the balloon

Weight of the balloon is dependent on the mass of the gas.

The weight of the gas is given by

$W = mg$

$W = 5\times9.8$

$W = 49\ N$

Hence, The the specific volume and weight are 79.16m³/k mol and 49 N.

7 0

4 years ago

Your friend says that the law of momentum conservation is violated when a ball rolls down a hill and gains momentum. What do you

pochemuha

Answer:

The friend is wrong: the law of conservation of momentum is not violated

Explanation:

The law of conservation of momentum states that:

"For a system of an object, if the net external force acting on the system is zero, then the total momentum of the system is conserved"

In our problem, the system is the ball rolling down the hill. The ball gains speed as it rolls down, so its momentum increases, according to the equation:

$p=mv$

where m is the mass of the ball and v its velocity. This may appear as a violation of the law, however it is not. In fact, the net external force acting on the ball is not zero, since there is the force of gravity acting on the ball. As a result, the force of gravity gives an acceleration to the ball, increasing its momentum: therefore, the law is not violated.

8 0

3 years ago