Give two examples where friction is a nuisance

If the distance between two masses is tripled, the gravitational force between changes by a factor of:_______

adell [148]

Answer:

option A

Explanation:

given,

distance between two masses is doubled

new distance, r' = 3 r

using gravitational force equation

$F = \dfrac{GMm}{r^2}$ ............(1)

new gravitational force

$F' = \dfrac{GMm}{r'^2}$

now from the given condition

$F' = \dfrac{GMm}{(3r)^2}$

$F' = \dfrac{GMm}{9r^2}$

$F' = \dfrac{1}{9}\dfrac{GMm}{r^2}$

now, from equation (1)

$F' = \dfrac{1}{9}F$

$\dfrac{F'}{F} = \dfrac{1}{9}$

now, the change in gravitational force factor is equal to $\dfrac{1}{9}$

Hence, the correct answer is option A

3 0

3 years ago

3. The propeller of a World War II fighter plane is 2.30 m in diameter. (a) What is its angular velocity in radians per second i

Darya [45]

Answer:

(a) Angular velocity will be 125.6 rad/sec

(b) Linear velocity will be 144.44 m /sec

(c) Centripetal acceleration = 1849.3031 g

Explanation:

We have given diameter d = 2.30 m

So radius r = $\frac{d}{2}=\frac{2.30}{2}=1.15m$

(a) Speed is given as 1200 rev/min

We know that angular velocity is given by $\omega =\frac{2\pi N}{60}=\frac{2\times 3.14\times 1200}{60}=125.6rad/sec$

(b) Linear speed is given by $v=\omega r=125.6\times 1.15=144.44m/sec$

(c) Centripetal acceleration is given by $a_c=\frac{v^2}{r}=\frac{144.44^2}{1.15}=18141.664m/sec^2$

We know that $g=9.81m/sec^2$

So $18141.66m/sec^2=\frac{18141.664}{9.81}=1849.3031g$

6 0

2 years ago

What is the speed that is measured in speedometer to track speed violation?

BartSMP [9]

Answer:

The officer's unit detects this 135-mile-per-hour speed and should subtract the patrol car's 70-mile -per-hour ground speed to get your true speed of 65 miles per hour. Instead, the officer's ground-speed beam fixes on the truck ahead and measures a false 50-mile-per-hour ground speed.

Explanation:

A speedometer or speed meter is a gauge that measures and displays the instantaneous speed of a vehicle. Now universally fitted to motor vehicles, they started to be available as options in the early 20th century, and as standard equipment from about 1910 onwards.

4 0

3 years ago

Roseanne heated a solution in a beaker as part of a laboratory experiment on energy transfer. After a while, she noticed the liq

Anna35 [415]

Water boilingis the answer

5 0

3 years ago

how does spatial pattern of heights illustrate the relationship between temperature density and the rate of vertical pressure ch

Anika [276]

The rate of change of vertical pressure is directly proportional to density and also directly proportional to temperature.

Generally, the relationship between temperature, density and rate of vertical pressure is given as;

$\rho = \frac{PM}{RT}$

$\frac{dP}{dz} = -\rho g\\\\$

where;

ρ is density
T is temperature
dP is rate of change of vertical pressure

Thus, from the formula above, we can conclude the following relationship between temperature, density and the rate of vertical pressure change in spatial pattern of heights.

The rate of change of vertical pressure is directly proportional to density and also directly proportional to temperature.

Learn more here:brainly.com/question/25395377

5 0

3 years ago