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3 years ago

Any change in an object's velocity is caused by

Physics

2 answers:

Archy [21]3 years ago

6 0

Answer:

<h3>C. an unbalanced force </h3>

Explanation:

<h3>I hope it helps ❤❤</h3>

Anarel [89]3 years ago

4 0

C. An unbalanced force

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¿Qué es la velocidad?

egoroff_w [7]

Velocidad-es una cantidad vectorial física; Tanto la magnitud como la dirección son necesarias para definirlo.

5 0

3 years ago

A ball is thrown vertically upwards with a velocity

zhuklara [117]

Answer:

Explanation:

The acceleration of gravity is 9.8m/s^2.

So to calculate the time it will take to make the ball stop(which btw means the ball now reach its greatest height), use the formula V1=V0+at. V1 is the final velocity(which is 0), V0 is the starting velocity(which is 30m/s), and the a(cceleration) is 9.8m/s^2.

(You can ignore the fact "at" is -30 instead 30, it's because the directions two velocity travel are opposite. )

We can now know the time it takes to make the ball stop just by the gravitational force is about 3 sec.

Use another formula S=1/2at^2, to find out the S(height) is 1/2*9.8*3^2=44.1, which is approximately D.45m .

6 0

3 years ago

A year 11 pupil with a mass of 55kg swinging back on their chair and falling off it at a speed of 0.6m/s. What is his kinetic en

posledela

Answer:

Uk = 9.9 J

Explanation:

To calculate the kinetic energie (Uk), you can make use of this formula:

Uk = 0.5 * m * v²

given m = 55 kg and v = 0.6 m/s

Substituting in the formula gives:

Uk = 0.5 * 55 * (0.6)²

Uk = 0.5 * 55 * 0.36

Uk = 9.9 J

Extra:

Now let's examine the formula in relation to the SI units. If you understand the following, it will give you great insight in how smart Phisics is inter twained by looking at formulas and their standard units. It will save you time in future to convert formulas, if you use the right standard units.

The formula for kinetic energie is:

Uk = 0.5 * m * v²

Standard SI unit for mass m is kg.

Standard SI unit for speed v is m/s.

So v * v = v² and therefore v² must have the standard SI unit of m²/s².

From the formula, you see that the unit of Uk must be kg*m²/s² and since Uk is normally given in J, these both forms must be the same !

The main unit for Uk is the Joule. Now please see the picture, which shows the relation between the J and other SI units. Please understand that you can construct your 'own' formulas based these units. Now here is the time saver:

Because almost always the right units are given in a question, or because sometimes you can look up a constant in a table with an exotic and seemingly complicated unit, but that says a lot about the formula which must have been some how involved!

By this, I hope you now understand the implication of using the right standard SI units and how that can help you figure out what formula is needed.

3 0

3 years ago

if a car that is 100 feet in front of you on route 70 west slams on the brakes while you are traveling 65 miles per hour (95 fee

fenix001 [56]

Answer:

t = 1.05 s

Explanation:

Given,

The distance between your vehicle and car, 100 ft

The constant speed of your vehicle, u = 95 ft/s

Since, the velocity is constant, a =0

If the car stopped suddenly, time left for you to hit the brake, t = ?

Using the second equation of motion,

S = ut + ½ at²

Substituting the given values in the equation

100 = 95 x t

t = 100/95

= 1.05 s

Hence, the time left for you to hit the brakes and stop before rear ending them, t = 1.05 s

5 0

3 years ago

What type of energy transfer occurs through light or electromagnetic waves?

Free_Kalibri [48]

Radiation is the transfer of heat energy through space by electromagnetic radiation. Most of the electromagnetic radiation that comes to the earth from the sun is in the form of visible light. Light is made of waves of different frequencies.

4 0

3 years ago

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