If an object is not moving, the forces acting upon it are...

A 3250-kg aircraft takes 12.5 min to achieve its cruising

scoundrel [369]

Answer:

effeciency n = = 49%

Explanation:

given data:

mass of aircraft 3250 kg

power P = 1500 hp = 1118549.81 watt

time = 12.5 min

h = 10 km = 10,000 m

v =85 km/h = 236.11 m/s

$n = \frac{P_0}{P}$

$P_o = \frac{total\ energy}{t} = \frac{ kinetic \energy + gravitational\ energy}{t}$

kinetic energy $= \frac{1}{2} mv^2 =\frac{1}{2} 3250* 236 = 90590389.66 kg m^2/s^2$

kinetic energy $= 90590389.66 kg m^2/s^2$

gravitational energy $= mgh = 3250*9.8*10000 = 315500000.00 kg m^2/s^2$

total energy $= 90590389.66 +315500000.00 = 409091242.28 kg m^2/s^2$

$P_o =\frac{409091242.28}{750} = 545454.99 j/s$

$effeciency\ n = \frac{P_o}{P} = \frac{545454.99}{1118549.81} = 0.49$

effeciency n = = 49%

8 0

3 years ago

Is the strange solid/liquid changing behavior of Oobleck the SAME as an ice cube melting?

Dmitrij [34]

I don’t think so because an ice cube melting needs heat and relies on temp while ooblecks transition from solid to quickly depends on force and speed

6 0

3 years ago

There is a 250-m-high cliff at half dome in yosemite national park in california. suppose a boulder breaks loose from the top of

lorasvet [3.4K]

Part A. For this part, we use two equations for linear motion:

y = y0 + v0 t + 0.5 g t^2 ---> 1

vf = v0 + g t ---> 2

First we solve for t using equation 1: y0 = 0 (initial point at top), y = 250 m, v0 = 0 (at rest)

250 = 0.5 (9.8) t^2

t = 7.143 s

Now we solve for final velocity vf using equation 2:

vf = g t

vf = 9.8 (7.143)

vf = 70 m/s

Part B. First we solve for the time it takes for the sound to reach the tourist.

t(sound) = 250 / 335 = 0.746 s

Therefore the total time would be:

t = 0.746 s + 0.300 s

t = 1.05 s

Hence there is enough time for the tourist to get out before the boulder hits him.

7 0

3 years ago

Read 2 more answers

Air resistance is a nonconservative force. It always opposes the motion of an object. An airplane flies from New York to Atlanta

Lorico [155]

Answer:

is always negative

Explanation:

Air resistance is a non-conservative force it opposes the motion of an object.It is a force that is always directed opposite to the displacement.

6 0

3 years ago

Read 2 more answers

4. Johnny exerts a 3.55 N rightward force on a 0.200-kg box to accelerate it across a low-friction track. If the total resistanc

Anon25 [30]

a) $15.2 m/s^2$

b) 1.96 N

c) 1.96 N

Explanation:

a)

To find the box's acceleration, we have to find first the net force acting on the box in the horizontal direction.

We have:

- The forward force of 3.55 N

- The backward, resistive force of 0.52 N

So, the net force forward is

$\sum F=3.55-0.52=3.03 N$

Now we can find the acceleration by using Newton's second law of motion, which states that:

$\sum F=ma$

where

m = 0.200 kg is the mass of the box

a is its acceleration

And solving for a, we find the acceleration:

$a=\frac{\sum F}{m}=\frac{3.03}{0.200}=15.2 m/s^2$

b)

The gravitational force on an object is the force with which the object is pulled towards the ground by the Earth.

It is given by

$W=mg$

where

m is the mass of the object

g is the gravitational field strength

In this problem we have

m = 0.200 kg is the mass of the box

$g=9.8 m/s^2$ is the gravitational field strength

So, the gravitational force on the box is

$W=(0.200)(9.8)=1.96 N$

c)

The normal force is the reaction force exerted by the floor on the box, in the upward direction.

In order to find the magnitude of this force, we apply Newton's second law of motion along the vertical direction.

We have two forces in this direction:

- The gravitational force, W, downward

- The normal force, N, upward

So the net force is

$\sum F=N-W$

According to Newton's second law,

$\sum F=ma$

However, the box is at rest in the vertical direction, so the vertical acceleration is zero:

$a=0$

This means that the net force is zero:

$\sum F=0$

And so, we can find the normal force:

$N-W=0\\N=W=1.96 N$

4 0

3 years ago