All categories

3 years ago

Q5: An ice skater moving at 12 m/s coasts

Physics

1 answer:

ExtremeBDS [4]3 years ago

8 0

u = 0.077

Explanation:

Work done by friction is

Wf = ∆KE + ∆PE

-umgx = ∆KE,. ∆PE =0 (level ice surface)

-umgx = KEf - KEi = -(1/2)mv^2

Solving for u,

u = v^2/2gx

= (12 m/s)^2/2(9.8 m/s^2)(95 m)

= 0.077

You might be interested in

If an input force of 202N is applied to the handles of the wheelbarrow in the sample problem how large is the output force that

Sloan [31]

For this case, the relationship between the two forces is given by:

F1 = nF2

Where,

F1: output strength
F2: input force
n: mechanical advantage

Then, replacing the values we have:

F1 = (2.2)(202)

Having the calculations we have:

F1 = 444.4N

Answer: The output force that only lifts the load is F1 = 444.4N.

3 0

3 years ago

an ice cube placed in microwave melts in five minutes and it takes 3.50 kj of energy to melt it. what is the power of the microw

Artist 52 [7]

If the ice absorbed 350,000 joules in 5 minutes, then it absorbed energy
at the rate of

(350,000 joules) / (5 x 60 seconds) = 1,166-2/3 watts .

Surely the ice cube didn't absorb every joule delivered to the cooking chamber,
so the microwave oven's cooking power had to be significantly more than that.

6 0

4 years ago

PLEASE HELP 15 POINTS AND BRAINIEST!!! Reporting fake answers

Leviafan [203]

The period, speed and acceleration of a satellite are only dependent upon the radius of orbit and the mass of the central body that the satellite is orbiting. I hope this helps. Sorry if i am wrong.

6 0

3 years ago

Which of the statements concerning light are true? The speed of light is the same no matter what material it is traveling throug

wel

Answer:

The statements that are true concerning light are the last three statements:

Its propagation direction is perpendicular to both the electric field and the magnetic field.

It moves at a constant speed through a vacuum.

The speed of light in matter is less than the speed of light in a vacuum.

Explanation:

Light is electromagnetic waves.

The properties of the electromagnetic waves were established by James Clerk Maxwell.

They included that they are the result of the oscillation of a magnetic field in phase with an electric field which are always is always perpendicular to each other.

Also, the electromagnetic waves propagate at right-angles to the direction of both the magnetic and the electric field, meaning that they are a type of transverse wave.

Thus, the second statement ("Its propagation direction is parallel to both the electric field and the magnetic field") is false, and the fourth statement ("Its propagation direction is perpendicular to both the electric field and the magnetic field") is true.

On the other hand, it is a postulate of the special theory of relativity that the speed of light is a constant (absolute value) in vacuum: nothing can travel faster than what light travels in vacuum. Thus, the fifth statement, "It moves at a constant speed through a vacuum" is true.

About the speed of light in matter, it is always less than the speed of light in vacuum. Thus, the first statement, "the speed of light is the same no matter what material it is traveling through", and the third statement "the speed of light in matter is greater than the speed of light in a vacuum" are false; while the last statement, "the speed of light in matter is less than the speed of light in a vacuum" is true.

The explanation on why the speed of light is less in a medium than in vacuum is related with the fact that at nanoscopic level the waves suffer polarization which means deviations from the straighi path, which makes that the net straight propagation is slower.

8 0

4 years ago

If two balls have the same volume,

Lena [83]

Here, we are required to find the relationship between balls of different mass(a measure of weight) and different volumes.

1. Ball A will have the greater density
2. Ball C and Ball D have the same density.
3. Ball Q will have the greater density.
4. Ball X and Y will have the same density

The density of an object is given as its mass per unit volume of the object.

Mathematically;.

Density = Mass/Volume.

For Case 1:

Va = Vb and Ma = 2Mb
D(b) = (Mb)/(Vb) and D(a) = 2(Mb)/Vb
Therefore, the density of ball A,
D(a) = 2D(b).
Therefore, ball A has the greater density.

For Case 2:

Vc = 3Vd,

Vd = (1/3)Vc

Md = (1/3)Mc

D(c) = (Mc)/(Vc) and D(d) = (1/3)Md/(1/3)Vd

D(c) = D(d).

Therefore, ball C and D have the same density

For Case 3:

Vp = 2Vq and Mp = Mq
D(p) = (Mq)/2(Vq) and D(q) = (Mq)/Vq
Therefore, the density of ball P is half the density of ball Q
Therefore, ball Q has the greater density.

For case 4:

Mx = (1/2)My
Vx = Vy

Therefore, Ball X and Ball Y have the same density.

Read more:

brainly.com/question/18110802

8 0

2 years ago