what 2 things can you do if you wanted to decrease an object's gravitational force? i'll mark brainliest!

All of the following are examples of ways to improve energy efficiency of heating systems, except _______.

Yuri [45]

Answer:

D. Opening the front door in winter to filter and clean warm ai

Explanation:

All of the following are examples of ways to improve energy efficiency of heating systems, except _______.

A. Closing off rooms that aren’t in use.

B. Frequently cleaning the furnace filter.

C. Fixing cracks in the walls and floor.

D. Opening the front door in winter to filter and clean warm air

for an heating systems it is better to keep the front door shut so that all the heat energy does not escape outside.

when heat energy is within a closed system ,it can still be utilized to keep the inhabitants warm otherwise there will be an exchange with the cold from winter fall outside the air, and the heating system's efficiency will be reduced

5 0

3 years ago

Which disease or disorder affects the lower respiratory system? Tuberculosis, laryngitis, sinus-itis, the common cold.

Wewaii [24]

Answer:

Tuberculosis

Explanation:

Tuberculosis is a disease of lower respiratory system because it's affect the lungs and the voice box . It is a bacteria disease that affect the lungs and it is very contagious. It can spread rapidly to the brain and spine. Most times people with tuberculosis did not show symptoms but when there is symptoms,the symptoms include cough with blood, night sweats, fever e t.c.

8 0

3 years ago

Read 2 more answers

A police officer in hot pursuit of a criminal drives her car through an unbanked circular (horizontal) turn of radius 300 m at a

Mamont248 [21]

Answer:

The angle (relative to vertical) of the net force of the car seat on the officer to the nearest degree is 10°.

Explanation:

Given:

Mass of the driver is, $m=55\ kg$

Radius of circular turn is, $R=300\ m$

Linear speed of the car is, $v=22.2\ m/s$

Since, the car makes a circular turn, the driver experiences a centripetal force radially inward towards the center of the circular turn. Also, the driver experiences a downward force due to her weight. Therefore, two forces act on the driver which are at right angles to each other.

The forces are:

1. Weight = $mg=55\times 9.8=539\ N$

2. Centripetal force, 'F', which is given as:

$F=\frac{mv^2}{R}\\F=\frac{55\times (22.2)^2}{300}\\\\F=\frac{55\times 492.84}{300}\\\\F=\frac{27106.2}{300}=90.354\ N$

Now, the angle of the net force acting on the driver with respect to the vertical is given by the tan ratio of the centripetal force (Horizontal force) and the weight (Vertical force) and is shown in the triangle below. Thus,

$\tan \theta=\frac{90.354}{539}\\\tan \theta=0.1676\\\theta=\tan^{-1}(0.1676)=9.52\approx 10$ °

Therefore, the angle (relative to vertical) of the net force of the car seat on the officer to the nearest degree is 10°.

3 0

2 years ago

Spider-Man and Ned were testing the distance he could shoot his web depending on the angle at which he points his web shooter. H

Serga [27]

Answer:

3. Madison, WI

4. Quito, Equador

6. Main Sequence stars are becoming red giants

Explanation:

3 0

3 years ago

Read 2 more answers

The rms (root-mean-square) speed of a diatomic hydrogen molecule at 50∘C is 2000 m/s. Note that 1.0 mol of diatomic hydrogen at

denis-greek [22]

Answer:

A) d. (1/4)(2000m/s) = 500 m/s

B) c. 4000 J

C) f. None of the above (2149.24 m/s)

Explanation:

A)

The translational kinetic energy of a gas molecule is given as:

K.E = (3/2)KT

where,

K = Boltzman's Constant = 1.38 x 1^-23 J/K

T = Absolute Temperature

but,

K.E = (1/2) mv²

where,

v = root mean square velocity

m = mass of one mole of a gas

Comparing both equations:

(3/2)KT = (1/2) mv²

v = √(3KT)/m _____ eqn (1)

FOR HYDROGEN:

v = √(3KT)/m = 2000 m/s _____ eqn (2)

FOR OXYGEN:

velocity of oxygen = √(3KT)/(mass of oxygen)

Here,

mass of 1 mole of oxygen = 16 m

velocity of oxygen = √(3KT)/(16 m)

velocity of oxygen = (1/4) √(3KT)/m

using eqn (2)

velocity of oxygen = (1/4)(2000 m/s) = 500 m/s

B)

K.E = (3/2)KT

Since, the temperature is constant for both gases and K is also a constant. Therefore, the K.E of both the gases will remain same.

K.E of Oxygen = K.E of Hydrogen

K.E of Oxygen = 4000 J

C)

using eqn (2)

At, T = 50°C = 323 k

v = √(3KT)/m = 2000 m/s

m = 3(1.38^-23 J/k)(323 k)/(2000 m/s)²

m = 3.343 x 10^-27 kg

So, now for this value of m and T = 100°C = 373 k

v = √(3)(1.38^-23 J/k)(373 k)/(3.343 x 10^-27 kg)

v = 2149.24 m/s

8 0

3 years ago