All categories

3 years ago

how many times does the kinectic energy of a car increase when traveling 60 mph as opposed to traveling 30 mph

1 answer:

3 0

The car at 60 kph has 9 times more kinetic energy than the car traveling at 20 kph. This assumes that both cars have the same mass. Kinetic energy depends on the square of thee speed so if one car is going 3 times faster, its kinetic energy will be 3^2 ( = 9 ) greater. The car going at 60 kph will have 4 times the KE of the car going at 30 kph ( again assuming that the cars have the same mass.)

You might be interested in

What type or types of movement occur in a hurricane as it moves along its track?

Ede4ka [16]

The answer to your question Tropical Cyclones

8 0

2 years ago

A horizontal block-spring system with the block on a frictionless surface has total mechanical energy E = 50.9 J and a maximum d

Llana [10]

(a) 2446 N/m

When the spring is at its maximum displacement, the elastic potential energy of the system is equal to the total mechanical energy:

$E=U=\frac{1}{2}kA^2$

where

U is the elastic potential energy

k is the spring constant

A is the maximum displacement (the amplitude)

Here we have

U = E = 50.9 J

A = 0.204 m

Substituting and solving the formula for k,

$k=\frac{2E}{A^2}=\frac{2(50.9)}{(0.204)^2}=2446 N/m$

(b) 50.9 J

The total mechanical energy of the system at any time during the motion is given by:

E = K + U

where

K is the kinetic energy

U is the elastic potential energy

We know that the total mechanical energy is constant: E = 50.9 J

We also know that at the equilibrium point, the elastic potential energy is zero:

$U=\frac{1}{2}kx^2=0$ because x (the displacement) is zero

Therefore the kinetic energy at the equilibrium point is simply equal to the total mechanical energy:

$K=E=50.9 J$

(c) 8.55 kg

The maximum speed of the block is v = 3.45 m/s, and it occurs when the kinetic energy is maximum, so when

K = 50.9 J (at the equilibrium position)

Kinetic energy can be written as

$K=\frac{1}{2}mv^2$

where m is the mass

Solving the equation for m, we find the mass:

$m=\frac{2K}{v^2}=\frac{2(50.9)}{(3.45)^2}=8.55 kg$

(d) 2.14 m/s

When the displacement is

x = 0.160 m

The elastic potential energy is

$U=\frac{1}{2}kx^2=\frac{1}{2}(2446)(0.160)^2=31.3 J$

So the kinetic energy is

$K=E-U=50.9 J-31.3 J=19.6 J$

And so we can find the speed through the formula of the kinetic energy:

$K=\frac{1}{2}mv^2 \rightarrow v=\sqrt{\frac{2K}{m}}=\sqrt{\frac{2(19.6)}{8.55}}=2.14 m/s$

(e) 19.6 J

The elastic potential energy when the displacement is x = 0.160 m is given by

$U=\frac{1}{2}kx^2=\frac{1}{2}(2446)(0.160)^2=31.3 J$

And since the total mechanical energy E is constant:

E = 50.9 J

the kinetic energy of the block at this point is

$K=E-U=50.9 J-31.3 J=19.6 J$

(f) 31.3 J

The elastic potential energy stored in the spring at any time is

$U=\frac{1}{2}kx^2$

where

k = 2446 N/m is the spring constant

x is the displacement

Substituting

x = 0.160 m

we find the elastic potential energy:

$U=\frac{1}{2}kx^2=\frac{1}{2}(2446)(0.160)^2=31.3 J$

(g) x = 0

The postion at that instant is x = 0, since it is given that at that instant the system passes the equilibrium position, which is zero.

4 0

2 years ago

Complete the sentences to describe the convection experiment.

riadik2000 [5.3K]

Answer:

The heat transfer model showed convection.

In the convection model, the red water on the bottom of the beaker is hot

This means that the water at the bottom of the beaker was less dense than the water near the top of the beaker.

Explanation:

Convection is the transference of heat energy by the movement (translation) of the particles of fluid (liquids or gases).

When the water on the bottom of the beaker is heated, it expands and becomes less dense.

The water near the top of the beaker is cold which makes it denser than the water at the bottom of the beaker.

Thus, the hot water from the bottom of the beaker will ascend toward the top of the beaker, while the cold water on top will descend toward the bottom. As long, as there is a difference of temperature between the water on the bottom and on top of the beaker, there will be a continuous movement of the particles: cold particles from the top replace hot particles from the bottom that ascend, and when the cold particles are heated they will ascend and will be replaced by new cold particles. This continuous translation of hot and cold particles in fluids is the model of heat transfer by convection.

4 0

3 years ago

Read 2 more answers

The distance between my home to school is 3 km and 240 m. what is the distance in km,m and dm

slamgirl [31]

Answer:

km = 3.24

m = 3,240

dm = 32,400

Explanation:

km = 1000m

m = 10dm