Ask question

Ask question

All categories

4 years ago

9

What is the change all living things undergo as the grow

1 answer:

Vladimir [108]4 years ago

6 0

All of the change that living things undergo as they grow is called development. That is the name when the changes are within a single unit and over a period of time as short as a lifetime. When the change occurs over thousands of years then it's called evolution.

You might be interested in

A hydrogen ion of mass 'm' and charge 'q' travels with a speed 'v' in a circle of radius 'r' in a magnetic field of intensity 'B

Allisa [31]

Answer:

$r=\frac{mv}{qB}$ , $T=\frac{2\pi m}{qB}$

Explanation:

The force experienced by the ion due to the magnetic field is given by:

$F=qvB$

where

q is the charge

v is the speed

B is the intensity of the magnetic field

The cetripetal force is

$F=\frac{mv^2}{r}$

where

m is the mass

r is the radius of the circle

Since the magnetic force acts as centripetal force, we can equate the two expressions:

$qvB=m\frac{v^2}{r}$

Re-arranging it, we find the radius:

$r=\frac{mv}{qB}$

Now, if we want to find the time it takes for the ion to make one complete circle (=the period), we just need to divide the length of one circumference by the speed:

$T=\frac{2\pi r}{v}$

And susbstituting the expression we found before for r, we find

$T=\frac{2\pi mv}{qBv}=\frac{2\pi m}{qB}$

8 0

3 years ago

How strong an electric field is needed to accelerate electrons in an X-ray tube from rest to one-tenth the speed of light in a d

Bond [772]

Answer:

E= 50.1*10³ N/C

Explanation:

Assuming no other forces acting on the electron, if the acceleration is constant, we can use the following kinematic equation in order to find the magnitude of the acceleration:

$vf^{2} -vo^{2} = 2*a*x$

We know that v₀ = 0 (it starts from rest), that vf = 0.1*c, and that x = 0.051 m, so we can solve for a, as follows:

$a = \frac{vf^{2}}{2*x} = \frac{(3e7 m/s)^{2} }{2*0.051m} =8.8e15 m/s2$

According to Newton's 2nd Law, this acceleration must be produced by a net force, acting on the electron.

Assuming no other forces present, this force must be due to the electric field, and by definition of electric field, is as follows:

F = q*E (1)

In this case, q=e= 1.6*10⁻19 C

But this force, can be expressed in this way, according Newton's 2nd Law:

F = m*a (2) ,

where m= me = 9.1*10⁻³¹ kg, and a = 8.8*10¹⁵ m/s², as we have just found out.

From (1) and (2), we can solve for E, as follows:

$E=\frac{me*a}{e} =\frac{(9.1e-31 kg)*(8.8e15m/s2)}{1.6e-19C} = 50.1e3 N/C$

⇒ E = 50.1*10³ N/C

3 0

4 years ago

A disk-shaped grindstone of mass 1.7 kg and radius 8 cm is spinning at 730 rev/min. After the power is shut off, a woman continu

Anastasy [175]

Answer:

0.186 N-m

Explanation:

mass of the grindstone, $m=1.7 kg$

radius, $r=8 cm$

Frequency, $f=730 rev/min = 12.16 rev/s$

time, $t=9s$

final angular velocity, $\omega=0$

Initial angular velocity,

$\omega_o=2\pi f\\=2\pi (12.16) rad/s\\= 76.36 rad/s$

Angular acceleration of the grind stone is:

$\alpha=\frac{\omega-\omega_o}{t}\\\Rightarrow \alpha =\frac{0-76.36}{9} = -8.48 rad/s^2$

Moment of inertia:

$I=mr^2+mr^2=2mr^2$

$I=2\times 1.7 kg\times (0.08m)^2= 0.022kg-m^2$

Torque exerted by the ax on the grind stone is:

$\tau=I\alpha\\\tau=0.022\times (-8.48) \\\tau=0.186N-m$

8 0

4 years ago

If a bicyclist, with initial velocity of zero, steadily gained speed until reaching a final velocity of 26m/s, how far would she

svetlana [45]

Answer:

34.45m

Explanation:

Using the equation of motion formula v² = u²+2as to get the distance travelled

v is the final velocity = 26m/s

u is the initial velocity = 0m/s

a is the acceleration due to gravity = 9.81m/s²

S is the distance travelled

Substituting the given values into the formula;

26² = 0²+2(9.81)s

676 = 0 + 19.62s

19.62s = 676

s = 676/19.62

s = 34.45m

Hence the distance she would travel during the race is 34.45m

7 0

3 years ago

_____ is very corrosive and can cause rusting so metal tanks shouldn't be used

bagirrra123 [75]

Answer:

Iron

Explanation:

5 0

3 years ago