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3 years ago

A thermos bottle works well because:

Physics

2 answers:

baherus [9]3 years ago

7 0

Answer:

A thermos bottle works well because:

A) Its glass walls are thin

soldi70 [24.7K]3 years ago

4 0

Answer:

A thermos bottle works well because:

Vacuum reduces heat radiation

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Why are there only two elements in the first period of the periodic table?(1 point)

tester [92]

Answer:

because each row increases in atomic mass by a specific number, so anything over five is in the second row.

8 0

2 years ago

A pendulum on earth swings with angular frequency ω. On an unknown planet, it swings with angular frequency ω/ 4. The accelerati

Afina-wow [57]

Answer:

g / 16

Explanation:

T = 2π $\sqrt{\frac{l}{g} }$

angular frequency ω = 2π /T

= $\sqrt{\frac{g}{l} }$

ω₁ /ω₂ = $\sqrt{\frac{g_1}{g_2} }$

Putting the values

ω₁ = ω , ω₂ = ω / 4

ω₁ /ω₂ = 4

4 = $\sqrt{\frac{g}{g_2} }$

g₂ = g / 16

option d is correct.

6 0

3 years ago

The temperature and time t given in hours from 0 to 24 after midnight in downtown mathville is given by t=10-5 sin(pi/12 t) degr

Dvinal [7]

Answer:

$T_A_v_g=9.918192559$^{\circ}C$

Explanation:

The problem tell us that the temperature as function of time in downtown mathville is given by:

$T(t)=10-5*sin(\frac{\pi}{12t})$

The average temperature over a given interval can be calculated as:

$T_a_v_g=\frac{T_o+T_f}{2}$

Where:

$T_o=Initial\hspace{3}temperature\\T_f=Final\hspace{3}temperature$

So, the initial temperature in this case, would be the temperature at noon, and the final temperature would be the temperature at midnight:

Therefore:

$T_o=T(12)=10-5*sin(\frac{\pi}{12*12}) =9.890925575$^{\circ}C$

$T_f=T(24)=10-5*sin(\frac{\pi}{12*24}) =9.945459543$^{\circ}C$

Hence, the average temperature between noon and midnight is:

$T_A_v_g=\frac{9.890925575+9.945459543}{2}=9.918192559$^{\circ}C$

3 0

3 years ago

. A spring has a length of 0.200 m when a 0.300-kg mass hangs from it, and a length of 0.750 m when a 1.95-kg mass hangs from it

kap26 [50]

Answer:

29.4 N/m

0.1

Explanation:

a) From the restoring Force we know that :

F_r = —k*x

the gravitational force :

F_g=mg

Where:

F_r is the restoring force .

F_g is the gravitational force

g is the acceleration of gravity

k is the constant force

xi , x2 are the displacement made by the two masses.

Givens:

m1 = 1.29 kg

m2 = 0.3 kg

x1 = -0.75 m

x2 = -0.2 m

g = 9.8 m/s^2

Plugging known information to get :

F_r =F_g

-k*x1 + k*x2=m1*g-m2*g

k=29.4 N/m

b) To get the unloaded length 1:

l=x1-(F_1/k)

Givens:

m1 = 1.95kg , x1 = —0.75m

Plugging known infromation to get :

l= x1 — (F_1/k)

= 0.1

3 0

3 years ago

According to the work-energy theorem, the amount of work done can be determined using which formula?

torisob [31]

Answer:

$W=\Delta KE= KE_f-KE_i=\frac{1}{2} \,m \,v_f^2-\frac{1}{2} \,m \,v_i^2$

Explanation:

The Work-Kinetic Energy Theorem states that the work done on a particle of mass "m", equals the particle's change in Kinetic Energy (final Kinetic Energy of the particle " $KE_f$ " minus the initial Kinetic energy of the particle " $KE_i$ "), and it is expressed as:

$W=\Delta KE= KE_f-KE_i=\frac{1}{2} \,m \,v_f^2-\frac{1}{2} \,m \,v_i^2$

where we have used the explicit form of the KE of a particle of mass m and velocity $v$ . Of course, $v_f$ stands for the final velocity of the particle, and $v_i$ for the particle's initial velocity.

6 0

3 years ago