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4 years ago

How do you measure velocity?

1 answer:

8 0

Speed and velocity are both measured using the same units. The SI unit of distance and displacement is the meter. The SI unit of time is the second. The SI unit of speed and velocity is the ratio of two — the meter per second.

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Optical tweezers use light from a laser to move single atoms and molecules around. Suppose the intensity of light from the tweez

Zanzabum

(a) $3.3\cdot 10^{-6} Pa$

The radiation pressure exerted by an electromagnetic wave on a surface that totally absorbs the radiation is given by

$p=\frac{I}{c}$

where

I is the intensity of the wave

c is the speed of light

In this problem,

$I=1000 W/m^2$

and substituting $c=3\cdot 10^8 m/s$ , we find the radiation pressure

$p=\frac{1000 W/m^2}{3\cdot 10^8 m/s}=3.3\cdot 10^{-6}Pa$

(b) $4.4\cdot 10^{-8} m/s^2$

Since we know the cross-sectional area of the laser beam:

$A=6.65\cdot 10^{-29}m^2$

starting from the radiation pressure found at point (a), we can calculate the force exerted on a tritium atom:

$F=pa=(3.3\cdot 10^{-6}Pa)(6.65\cdot 10^{-29} m^2)=2.2\cdot 10^{-34}N$

And then, since we know the mass of the atom

$m=5.01\cdot 10^{-27}kg$

we can find the acceleration, by using Newton's second law:

$a=\frac{F}{m}=\frac{2.2\cdot 10^{-34} N}{5.01\cdot 10^{-27} kg}=4.4\cdot 10^{-8} m/s^2$

6 0

3 years ago

Relative motion can best be defined as

creativ13 [48]

Relative motion is the motion of an object relative to another object,
or as it would appear to an observer stuck to the other object and
riding on it.

6 0

3 years ago

Among oil field buddies, Conrad was known as a cheerfully profane, hard drinker who was seldom averse to a barroom scrap. But, a

Sholpan [36]

Conrad’s physician has determined that the damaged that causes his change of behavior is the amygdala. The amygdala is the gray matter of the cerebral hemisphere in which is responsible for making an individual have emotions for it is the emotional center. Thus, it makes Conrad changed because this could have been damaged, making his behavior to change.

8 0

4 years ago

Read 2 more answers

True or false? a physical change is a change of matter from one form to another without a change in chemical properties

Lina20 [59]

The answer is true!!!

6 0

3 years ago

A rubber ball and a lump of clay have equal mass. They are thrown with equal speed against a wall. The ball bounces back with ne

gregori [183]

Answer:

The ball experiences the greater momentum change

Explanation:

The momentum change of each object is given by:

$\Delta p = m \Delta v= m (v-u)$

where

m is the mass of the object

v is the final velocity

u is the initial velocity

Both objects have same mass m and same initial velocity u. So we have:

- For the ball, the final velocity is

$v=-u$

Since it bounces back (so, opposite direction --> negative sign) with same speed (so, the magnitude of the final velocity is still u). So the change in momentum is

$\Delta p=m(v-u)=m((-u)-u)=-2mu$

- For the clay, the final velocity is

$v=0$

since it sticks to the wall. So, the change in momentum is

$\Delta p = m(v-u)=m(0-u)=-mu$

So we see that the greater momentum change (in magnitude) is experienced by the ball.

3 0

3 years ago