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3 years ago

Select the correct text in the passage.

Physics

2 answers:

kompoz [17]3 years ago

7 0

Answer:

However, occasionally, the planet will seem to reverse direction, and for a short time appears to move from east to west.

serious [3.7K]3 years ago

4 0

Answer:

I have no clue

Explanation:

i just have no clue

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If the jet is moving at a speed of 1140 km/h at the lowest point of the loop, determine the minimum radius of the circle so that

AnnZ [28]

To solve this problem we will apply the concepts related to the centripetal Force and the Force given by weight and formulated in Newton's second law. Through the two expressions we can find the radius of curve made in the hand. To calculate the normal force, we will include the concepts of sum of forces to obtain the net force on the body at the top and bottom of the maneuver. The expression for centripetal force acting on the jet is

$F_c = \frac{mv^2}{r}$

According to Newton's second law, the net force acting on the jet is

F = ma

Here,

m = mass

a = acceleration

v = Velocity

r = Radius

PART A ) Equating the above two expression the equation for radius is

$\frac{mv^2}{r} = ma$

$r = \frac{v^2}{a}$

Replacing with our values we have that

$r = \frac{(1140km/hr[\frac{1000m}{1km}\frac{1hour}{3600s}])^2}{7(9.8m/s^2)}$

$r = 1.462*10^3m$

PART B )

- The expression for effective weight of the pilot at the bottom of the circle is

$N = mg +\frac{mv^2}{r}$

$N = (69kg)(9.8m/s^2)+\frac{(69)(1140km/hr[\frac{1000m}{1km}\frac{1hour}{3600s}])^2}{1.462*10^3m}$

$N = 5408.87N$

Note that the normal reaction N is directed upwards and gravitational force mg is directed downwards. At the bottom of the circle, the centripetal force is directed upwards. So the centripetal force is obtained from the gravitational force and the normal reaction.

- The expression for effective weight of the pilot at the top of the circle is

$N = mg -\frac{mv^2}{r}$

$N = (69kg)(9.8m/s^2)-\frac{(69)(1140km/hr[\frac{1000m}{1km}\frac{1hour}{3600s}])^2}{1.462*10^3m}$

$N = 4056.47N$

Note that at the top of the circle the centripetal force is directed downwards. So the centripetal force is obtained from normal reaction and the gravitational force.

4 0

3 years ago

A tennis ball with mass m travelling west,hits a wall with a velocity of v.It bounces back with a velocity 1 ,63 v an easterly d

Pepsi [2]

Answer:

163 v an easterly direction

6 0

3 years ago

In comparing molar specific heat for gases under constant pressure CP and constant volume CV, we conclude that (more than one co

Sauron [17]

Answer:

b. Specific heat increases as the number of atoms per molecule increases.

c. Specific heat at constant pressure is higher than at constant volume.

d. Monatomic gases behave like ideal gases.

Explanation:

Specific heat of the gas at constant pressure is usually higher than that of the volume.

i.e.

Cp - Cv = R

where R is usually the gas constant.

However, monoatomic gases are gases that exhibit the behavior of ideal gases. This is due to the attribute of the intermolecular forces which plays a negligible role. Nonetheless, the case is not always true for all temperatures and pressure.

Similarly, the increase in the number of atoms per molecule usually brings about an increase in specific heat. This effect is true as a result of an increase in the total number associated with the degree of freedom from which energy can be separated.

Thus, from above explanation:

Option b,c,d are correct while option (a) is incorrect.

4 0

3 years ago

If you walk at an average speed of 5 km/h for 30 minutes, how

timurjin [86]

Time= s/v

Speed =5km/h
Time=30min
Distance is required
Distance=time*speed
30min*5km/h=600m

4 0

3 years ago

A 3kg book falls from a shelf. If it lands with a speed of 4.8 m/s, from what height did it fall? A. 28.8 m , B. 1.2 m , C. 0.6

Irina-Kira [14]

The correct answer is B. 1.2 m (apex)

7 0

3 years ago