If a net force of 20 N is applied to a mass of 4kg, what is the acceleration

The concrete slab of a basement is 11 m long, 8 m wide, and 0.20 m thick. During the winter, temperatures are nominally 17°C and

mina [271]

Answer:

$\frac{dQ}{dt}= 4312 W$

Explanation:

As we know that base of the slab is given as

$A = 11 \times 8$

$A = 88 m^2$

now we know that rate of heat transfer is given as

$\frac{dQ}{dt} = \frac{kA}{x} (T_2 - T_1)$

here we know that

$k = 1.4 W/m k$

Also we have

$x =0.20$

$\frac{dQ}{dt} = \frac{1.4(88)}{0.20}(17 - 10)$

$\frac{dQ}{dt}= 4312 W$

7 0

3 years ago

You have a rock sample and analyze it for the presence of radioactive isotopes in order to determine when it was formed. You fin

Firdavs [7]

Answer:

the decay of half of the nuclei only a half-life has passed , b) in rock time it is 1 108 years

Explanation:

The radioactive decay is given by

N = N₀ $e^{\lambda t}$

If half of the atoms have decayed

½ N₀ = N₀ $e^{\lambda t}$

½ = $e^{\lambda t}$ ₀

Ln 0.5 = - λ t

t = - ln 0.5 /λ

The definition of average life time is

$T_{1/2}$ = ln 2 / λ

λ = ln 2 / $T_{1/2}$

λ = 0.693 / 100 10⁶

λ = 0.693 10⁻⁸ years

We replace

t = -ln 0.5 / 0.693 10⁻⁸

t = 10⁸ years

We see that for the decay of half of the nuclei only a half-life has passed

b) in rock time it is 1 108 years

8 0

3 years ago

Reuptake refers to the...

Arada [10]

Reuptake refers to the REABSORPTION of excess neurotransmitter molecules by a sending neuron (Option b).

Reuptake is the mechanism by which cells reabsorb chemical messengers produced and secreted by them. In nerve terminals, reuptake is used to reabsorb released neurotransmitters.

The reuptake mechanism is exploited in therapeutics for the development of target drugs and treatments.

Serotonin is a neurotransmitter that acts to stabilize different emotions such as mood, feelings of well-being, appetite and happiness.

For example, serotonin reuptake inhibitors which are capable of blocking the reuptake of serotonin to modulate serotonin brain levels have recently been developed.

Learn more in:

brainly.com/question/4439815?referrer=searchResults

4 0

1 year ago

An object undergoes two successive displacements:

Gre4nikov [31]

The magnitude of the net displacement is 95.3 m

Explanation:

To find the magnitude of the net displacement, we have to resolve each of the two displacements into the horizontal and vertical direction first.

1st displacement is:

$d_1=79 m$ at $16.9^{\circ}$

So its components are

$d_{1x}=(79)(cos 16.9^{\circ})=75.6 m\\d_{1y}=(79)(sin 16.9^{\circ})=23.0 m$

2nd displacement is:

$d_2=16.7 m$ at $31.1^{\circ}$

So its components are

$d_{2x}=(16.7)(cos 31.1^{\circ})=14.3 m\\d_{2y}=(16.7)(sin 31.1^{\circ})=8.6 m$

Therefore, the x- and y-components of the net displacement are:

$d_x=d_{1x}+d_{2x}=75.6+14.3=89.9 m\\d_y=d_{1y}+d_{2y}=23.0+8.6=31.6 m$

Therefore, the magnitude of the final displacement is:

$d=\sqrt{d_x^2+d_y^2}=\sqrt{(89.9)^2+(31.6)^2}=95.3 m$

Learn more about displacement:

brainly.com/question/3969582

#LearnwithBrainly

8 0

2 years ago

Sammy feels an ocean breeze as he plays volleyball at the beach. Why do ocean winds or sea breezes blow toward shore during the

DedPeter [7]

The heat coming from the sun warms the land more quickly than the sea. As a result of these, the air near the land warm up and rises and the cooler air from the sea moves in to replace the risen air. The correct answer is option A

There will be heat transfer from a region of higher temperature to the region of lower temperature. But in the case of land and sea breeze, the transfer of heat are the result of convectional current in nature. Because the land is a better absorber of heat and also has a lower specific heat capacity compare to sea, during the day, the heat coming from the sun warms the land more quickly than the sea. As a result of these, the air near the land warm up and rises.

The cooler air from the sea moves in to replace the risen air.

Why do ocean winds or sea breezes blow toward shore during the day ? It is because air over the beach heats up, rises and is replaced by ocean air.

Therefore, option A is correct

Learn more here : brainly.com/question/1114842

4 0

2 years ago

If a net force of 20 N is applied to a mass of 4kg, what is the acceleration​

If a net force of 20 N is applied to a mass of 4kg, what is the acceleration