Whitch two options are forms of kinetic energy?

A hose directs a horizontal jet of water, moving with a velocity of 20m/s, on to a vertical wall. The

just olya [345]

Force is defined as the rate of change of momentum.
The initial amount of momentum is $mv$ because water stops when it hit the wall total change of momentum must be $\Delta p=mv$ .
Now let's calculate the force.
$F= \frac{dp}{dt}=\frac{d(mv)}{dt}=\frac{dm}{dt}v$
We need to find $\frac{dm}{dt}$ . This is the amount of water hiting the wall per second.
$\frac{dm}{dt}=\rho Av$
Our final formula would be:
$F=\rho Avv=\rho Av^2$
And now we can calculate the answer:
$F=1000\cdot5\cdot 10^{-4}\cdot(20)^2=200 N$

6 0

3 years ago

Solve:40KMEN

Oksanka [162]

The spider will cross the driveway 25.71 in seconds.

Why?

It's a conversion problem, so, in order to solve it, we need to convert the units of the given information.

Let's convert the given speed (in cm/s) to m/s.

We know that:

$1m=100cm$

So, converting we have:

$14\frac{cm}{s}*\frac{1m}{100cm}=0.14\frac{m}{s}$

Then, calculating the time, we have:

$distance=speed*time\\\\3.6m=0.14\frac{m}{s}*time\\\\time=\frac{3.6m}{0.14\frac{m}{s}}=25.71s$

We have that the spider will cross the driveway in 25.71 seconds.

Have a nice day!

8 0

4 years ago

Two 5.0 kilogram objects have different gravitational potential energies. What property of the objects must differ?

ipn [44]

Answer:

Height.

Explanation:

Potential energy can be defined as an energy possessed by an object or body due to its position.

Mathematically, potential energy is given by the formula;

$P.E = mgh$

Where,

P.E represents potential energy measured in Joules.

m represents the mass of an object.

g represents acceleration due to gravity measured in meters per seconds square.

h represents the height measured in meters.

Hence, the property of the object (having a mass of 5 kilograms) which must differ to have different gravitational potential energies is the height from which they are falling from.

The object having the higher height would have a greater gravitational potential energy than the lower object.

7 0

3 years ago

A water tower is a familiar sight in many towns. The purpose of such a tower is to provide storage capacity and to provide suffi

Mademuasel [1]

The image of the water tower and the houses is in the attachment.

Answer: (a) P = 245kPa;

(b) P = 173.5 kPa

Explanation: Gauge pressure is the pressure relative to the atmospheric pressure and it is only dependent of the height of the liquid in the container.

The pressure is calculated as: P = hρg

where

ρ is the density of the liquid, in this case, water, which is ρ = 1000kg/m³;

When it is full the reservoir contains 5.25×10⁵ kg. So, knowing the density, you know the volume:

ρ = $\frac{m}{V}$