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3 years ago

Which of the following statements is/are true? Check all that apply.

Physics

1 answer:

Digiron [165]3 years ago

6 0

Answer:

The statements which are true are:

1) A person's power output limits the amount of work that he or she can do in a given time span.

2) The SI unit of power is the watt.

4) Power can be considered the rate at which work is done.

Explanation:

Power can be defined as the the rate at which the work is done. Mathematically,

$\large{P = \dfrac{W}{t}}$

where ' $W$ ' is the amount of work done in time ' $t$ '.

Also one can perform some work in the expense of the energy that he/she consumes. So alternatively power can also be defined as the rate at which the energy is expended.

The SI unit of work done is Joule. So the unit of power in SI system is

$Js^{-1}$ or Watt.

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The cross sectional area of Sphere 2 is increased to 3 times the cross sectional area of Sphere 1. The masses remain 1.0 kg and

ira [324]

Complete question is;

a. Two equal sized and shaped spheres are dropped from a tall building. Sphere 1 is hollow and has a mass of 1.0 kg. Sphere 2 is filled with lead and has a mass of 9.0 kg. If the terminal speed of Sphere 1 is 6.0 m/s, the terminal speed of Sphere 2 will be?

b. The cross sectional area of Sphere 2 is increased to 3 times the cross sectional area of Sphere 1. The masses remain 1.0 kg and 9.0 kg, The terminal speed (in m/s) of Sphere 2 will now be

Answer:

A) V_t = 18 m/s

B) V_t = 10.39 m/s

Explanation:

Formula for terminal speed is given by;

V_t = √(2mg/(DρA))

Where;

m is mass

g is acceleration due to gravity

D is drag coefficient

ρ is density

A is Area of object

A) Now, for sphere 1,we have;

m = 1 kg

V_t = 6 m/s

g = 9.81 m/s²

Now, making D the subject, we have;

D = 2mg/((V_t)²ρA))

D = (2 × 1 × 9.81)/(6² × ρA)

D = 0.545/(ρA)

For sphere 2, we have mass = 9 kg

Thus;

V_t = √[2 × 9 × 9.81/(0.545/(ρA) × ρA))]

V_t = 18 m/s

B) We are told that The cross sectional area of Sphere 2 is increased to 3 times the cross sectional area of Sphere 1.

Thus;

Area of sphere 2 = 3A

Thus;

V_t = √[2 × 9 × 9.81/(0.545/(ρA) × ρ × 3A))]

V_t = 10.39 m/s

5 0

4 years ago

A 7.7cm length of straight wire run horizontally along a north south line . The wire carries a 3.45 current flowing northward th

Maurinko [17]

Answer:

F = 0.332 N in the east direction

Explanation:

Length, L = 7.7 cm = 7.7 * 0.01 = 0.077 m(along the north south)

Current, I = 3.45 A (northwards)

Magnetic field, B = 1.25 T (vertically upwards)

The magnitude of the force is given by, F = ILBsin90

F = 3.45 * 0.077 * 1.25 * 1

F = 0.332 N

The direction of the force is calculated using the Right Hand Thumb Rule:

It states that "Hold the wire carrying current in your right hand so that the thumb points along the wire in the direction of the current, then the fingers will encircle the wire in the direction of the lines of magnetic force."

Based on the Right Hand Thumb Rule, the magnetic force will act in the east direction

3 0

3 years ago

Which term describes the amount of water vapor in the air?

loris [4]

That would be humidity

4 0

3 years ago

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The impulse experienced by a body is equivalent to the body’s change in

nika2105 [10]

<h2>Answer: </h2>

Momentum

<h2>Explanation: </h2>

The momentum of a particle is defined as the product of the particle mass and the particle velocity as follows:

$\overrightarrow{p}=m\overrightarrow{v}$

On the other hand, the impulse of a constant force is defined as:

$\overrightarrow{J}=\varSigma\overrightarrow{F}(t_{2}-t_{1})=\varSigma\overrightarrow{F}\Delta t$

We also know that the net force acting on a particle equals the rate of change of the particle’s momentum, so:

$\varSigma\overrightarrow{F}=m\overrightarrow{a}=m\frac{d}{dt}(\overrightarrow{v})=\frac{d}{dt}(m\overrightarrow{v})=\frac{d\overrightarrow{p}}{dt}$

If the force is constant, then $\frac{d\overrightarrow{p}}{dt}$ equals the total change in momentum over a period of time:

$\varSigma\overrightarrow{F}=\frac{\overrightarrow{p_{2}}-\overrightarrow{p_{1}}}{t_{2}-t_{1}} \\ \\ \varSigma\overrightarrow{F}(t_{2}-t_{1})=\overrightarrow{p_{2}}-\overrightarrow{p_{1}} \\ \\ \boxed{\overrightarrow{J}=\Delta \overrightarrow{p}}$

3 0

3 years ago

What affect does doubling the net force have on the acceleration of the object (when

Triss [41]

<h3>Answer: The acceleration doubles</h3>

===========================================================

Explanation:

Consider a mass of 10 kg, so m = 10

Let's say we apply a net force of 20 newtons, so F = 20

The acceleration 'a' is...

F = ma

20 = 10a

20/10 = a

2 = a

a = 2

The acceleration is 2 m/s^2. Every second, the velocity increases by 10 m/s.

---------------

Now let's double the net force on the object

F = 20 goes to F = 40

m = 10 stays the same

F = ma

40 = 10a

10a = 40

a = 40/10

a = 4

The acceleration has also doubled since earlier it was a = 2, but now it's a = 4.

---------------

In summary, if you double the net force applied to the object, then the acceleration doubles as well.

8 0

3 years ago

Read 2 more answers