The answer is A.
The brain sends signals by chemical reactions that occur in the neurons to the muscle cells.
The muscle cells, after receiving the signals sent by brain, contract and expand necessarily to execute the action, in other words, it performs work.
Hope this helps you! :)

6 0

3 years ago

In a crash test, a car with a mass of 1600 kg is initially moving at a speed of 20 m/s just before it collides with a barrier. T

Andrews [41]

Answer:

The answer to the given points can be defined as follows:

Explanation:

In point 1:

$\bold{v_f^2= v_i^2+2as}\\\\\to v_f=0\\\\\to v_i=20 \frac{m}{s}\\\\\to s= 4.50\ m -3.60 \ m \\\\$

$=0.9 \ m \\$

put the value in the above formula:

$\to 0= 20^2+2 \times a \times 0.9\\\\\to -1.8\ a=400\\\\\to -a= \frac{400}{1.8} \\\\ \to a= -222.22\ \ \frac{m}{s^2}$

$\bold{v_f=v_i+at}\\\\\to 0=20+ (-222.22)t\\\\\to 222.22t=20\\\\\to t=\frac{20}{222.22}\\\\\to t= 0.0900 \ s\\\\\to v_{avg}=\frac{s}{t}=\frac{0.9}{t}= 10\ \frac{m}{s}$

for point 2:

$t= 0.0900 \ s -\text{found above}$

for point 3:

$\to |a| = 222.22 \frac{m}{s^2} \text{found above}\\\\\to \bold{|F| = m \cdot |a|}\\\\$

$=1600 \ kg \times 222.22 \ \frac{m}{s^2} \\\\= 3.55\times 10^{5} \ N$

5 0

3 years ago

A battery can be modeled as a source of emf in series, with both a resistance of 10Ωand an inductive reactance of 5

Fiesta28 [93]

Answer:

Explanation:

For circuit in resonance , inductive and capacitive reactance should be equal. Since in the given circuit , these two are not equal, the circuit is not in resonance. It does not depend upon voltage provided.

option b is correct.

With this load, the fraction of the average power, put out by the source of emf, delivered to the load can be calculated as follows

Power delivered to resistor will be 2/3 rd of total power delivered by source because resistance has value twice that of reactance of capacitor. So the correct option is .7

option D ) is correct.

3 0

4 years ago