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3 years ago

What is the kinetic energy of a 5-kg object moving at 7 m/s?

1 answer:

6 0

To answer this question, we would need the formula for the kinetic energy which is Kinetic Energy = ½ x m x v^2

Where the following means: m is the mass of the object and v is the velocity

So At 7 m/s: Kinetic Energy = ½ x 5 x 7^2 = 122.5 J is the answer

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How can a 1kg ball have more kinetic energy than a 100kg ball? Explain both using words and by providing a numerical example

MariettaO [177]

1 kg ball can have more kinetic energy than a 100 kg ball as increase in velocity is having greater impact on K.E than increase in mass.

Explanation:

We know kinetic energy can be judged or calculated by two parameters only which is mass and velocity. As kinetic energy is directly proportional to the $(velocity)^2$ and increase in velocity leads to greater effect on translational Kinetic Energy. Here formula of Kinetic Energy suggests that doubling the mass will double its K.E but doubling velocity will quadruple its velocity:

$\text { Kinetic Energy }=\frac{1}{2} m v^{2}$

Better understood from numerical example as given:

If a man A having weight 50 kg run with speed 5 m/s and another man B having 100 kg weight run with 2.5 m / s. Which man will have more K.E?

This can be solved as follows:

$\text { Kinetic Energy of } \mathrm{A}=\frac{1}{2} 50 \times 5^{2}=625 \mathrm{J}$

$\text { Kinetic Energy bf } \mathrm{B}=\frac{1}{2} 100 \times 2.5^{2}=312.5 \mathrm{J}$

It shows that man A will have more K.E.

Hence 1 kg ball can have more K.E than 100 kg ball by doubling velocity.

4 0

3 years ago

He does whatever a spider can. Spider-Man, who has a mass of 76 [kg], is clinging onto an inclined wall forming an inclination a

Aliun [14]

Answer:570.54 N

Explanation:

Given

mass of man=76 kg

$\theta =50^{\circ}$

As man is standing over inclined building therefore

its weight has two components i.e. sin and cos component

Force perpendicular to inclined wall

$F=mgcos\theta =76\times 9.8\times \sin 50$

F=570.54 N

4 0

3 years ago

The current through a 0.2-H inductor is i(t) = 10te–5t A. What is the energy stored in the inductor?

lakkis [162]

Answer:

E = 10t^2e^-10t Joules

Explanation:

Given that the current through a 0.2-H inductor is i(t) = 10te–5t A.

The energy E stored in the inductor can be expressed as

E = 1/2Ll^2

Substitutes the inductor L and the current I into the formula

E = 1/2 × 0.2 × ( 10te^-5t )^2

E = 0.1 × 100t^2e^-10t

E = 10t^2e^-10t Joules

Therefore, the energy stored in the inductor is 10t^2e^-10t Joules

6 0

3 years ago

What is the relationship between air pressure and air temperature?

LenKa [72]

The relationship between the two is that air temperature changes the air pressure. For example, as the air warms up the molecules in the air become more active and they use up more individual space even though there is the same number of molecules. This causes an increase in the air pressure.

8 0

3 years ago

Is vapor pressure independent of atmospheric pressure? - This is what my instructor told me, but I don't understand why. ...?

miss Akunina [59]

Vapor pressure or equilibrium vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases at a certain temperature. It is independent with atmospheric pressure since it does not change by changing the atmospheric pressure only.

5 0

3 years ago