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3 years ago

Arunner starts from rest and accelerates uniformly to a speed of 8.0 meters per

Physics

1 answer:

VladimirAG [237]3 years ago

3 0

Answer:

2.0 m/s/s

Explanation:

The acceleration of an object is the rate of change of velocity of the object.

Mathematically, it is given by:

$a=\frac{v-u}{t}$

where

u is the initial velocity

v is the final velocity

t is the time taken for the velocity to change from u to v

Acceleration is a vector, so it has both a magnitude and a direction.

For the runner in this problem, we have:

u = 0 is the initial velocity (he starts from rest)

v = 8.0 m/s is the final velocity

t = 4.0 s is the time taken

Substituting, we find

$a=\frac{8.0-0}{4.0}=2.0 m/s^2$

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Consider a parachutist that has reached terminal velocity. which of the following is true? A.) The acceleration of the parachuti

trasher [3.6K]

The correct answer is:
<span>B.) At terminal velocity there is no net force

In fact, when the parachutist reaches the terminal velocity, his velocity does not change any more. It means that the acceleration acting on the parachutist is zero, and for Newton's second law, this means the net force acting on him is zero:
</span> $\sum F = ma = 0$
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3 years ago

True or False:

bekas [8.4K]

I think it false. Sorry if i'm wrong.

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3 years ago

Read 2 more answers

What is the magnitude of the electric field at a distance of 89 cm from a 27 μC charge, in units of N/C?

GuDViN [60]

Answer:

306500 N/C

Explanation:

The magnitude of an electric field around a single charge is calculated with this equation:

$E(r) = \frac{1}{4 \pi *\epsilon 0} \frac{q}{r^2}$

With ε0 = 8.85*10^-12 C^2/(N*m^2)

Then:

$E(0.89) = \frac{1}{4 \pi *8.85*10^-12} \frac{27*10^-6}{0.89^2}$

E(0.89) = 306500 N/C

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3 years ago

Bruno the bat flies at a speed of 0.5 m/s in circle of radius 1 m. What is his acceleration?

beks73 [17]

Answer:

Acceleration is 0.25m/s^2

Explanation:

Given the following :

Speed = 0.5m/s

Radius(r) of circle = 1m

Acceleration round a circular path is given as :

a = v^2 / r

Where

a = acceleration of the body

v = speed / velocity

r = radius

Therefore,

a = v^2 / r

a = (0.5)^2 / 1

a = 0.25m/s^2

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3 years ago

The rate (in cubic feet per hour) that a spherical snowball melts is proportional to the snowball's volume raised to the 2/3 pow

Darina [25.2K]

Answer:

A 3 feet radius snowball will melt in 54 hours.

Explanation:

As we can assume that the rate of snowball takes to melt is proportional to the surface area, then the rate for a 3 feet radius will be:

T= A(3 ft)/A(1 ft) * 6 hr

A is the area of the snowballs. For a spherical geometry is computing as:

A=4.pi.R^2

Then dividing the areas:

A(3 feet)/A(1 foot) = (4 pi (3 ft)^2)/(4 pi (1 ft)^2) = (36pi ft^2)/(4pi ft^2)= 9

Finally, the rate for the 3 feet radius snowball is:

T= 9 * 6 hr = 54 hr

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3 years ago