All categories

1 year ago

How do Leeuwenhoek’s observations of animalcules compare to Hooke’s observations of cells in the cork?

Physics

1 answer:

fomenos1 year ago

8 0

Answer:

Robert Hooke

Was the first to use the word "cell"

Observed cork cells

Anton van Leeuwenhoek

Observed "animalcules"

Used polished lens .

Explanation:

Anton van Leeuwenhoek is known as father of microbiology. He is credited to improve the quality of lens in microscope. His first observation of organisms called animalcules.

He is credited to have build microscope that could get magnified by 200 times. He used word animalcules for small organisms from pond water when first observed in microscope. He discovered protozoa and named it animalcules".

Robert Hooke is famed for discovering cell from a cork of plant. He observed a compartment or honey comb like divisions when observed these cork cells under the microscope and named it cell. He was only able to see the cell wall as the cork cells are dead cells.

You might be interested in

A 1000.–kilogram car traveling 20.0 meters per second east experiences an impulse of 2000. newton • seconds west. What is the fi

emmainna [20.7K]

Impulse is equal to change in momentum. So if impulse is 2000 then to solve for new velocity we just set it equal to equation for momentum.

First find original momentum by p=mv
p=1000*20=20000

So then taking that value minus the impulse since it was in opposite direction of original momentum it will slow it down some. To find new velocity we just take

20000-2000=18000=mv

v=18000/1000 =18m/s

Hope this helps!! Any questions please ask!!
Thank you!

5 0

1 year ago

Approximately 1.000 g each of four gasses H2, Ne, Ar, and Kr are placed in a sealed container all under1.5 atm of pressure. Assu

Vera_Pavlovna [14]

Answer:

The partial pressure of H2 is 0.375 atm

The partial pressure of Ne is also 0.375 atm

Explanation:

Mass of H2 = 1 g

Mass of Ne = 1 g

Mass of Ar = 1 g

Mass of Kr = 1 g

Total mass of gas mixture = 1 + 1 + 1 + 1 = 4 g

Pressure of sealed container = 1.5 atm

Partial pressure of H2 = (mass of H2/total mass of gas mixture) × pressure of sealed container = 1/4 × 1.5 = 0.375 atm

Partial pressure of Ne = (mass of Ne/total mass of gas mixture) × pressure of sealed container = 1/4 × 1.5 = 0.375 atm

7 0

2 years ago

Bianca is standing at x =600m. Firecracker 1, at the origin, and firecracker 2, at x =900m, explode simultaneously. The flash fr

agasfer [191]

Answer: $3 \mu s$

Explanation:

Given

Bianca is at $x=600 m$

i.e. distance between origin and Bianca is $600 m$

time taken to reach Bianca eyes is

$t=\frac{600}{speed\ of\ light}$

$t=\frac{600}{3\times 10^8}$

$t=2\times 10^{-6} s$

$t=2 \mu s$

i.e. Cracker exploded at $t=2\mu s$ because it is observed at $t=4\mu s$

Time taken by second cracker flash to reach Bianca eyes

$t_2=\frac{300}{3\times 10^8}$

$t_2=10^{-6}$

$t_2=1 \mu s$

Therefore it will be observed at $t=3 \mu s$

4 0

2 years ago

what is the speed of a 2.5-kilogram mass after ot has fallen freely from rest through a distance of 12 meters? a) 4.8 m/s b) 15

larisa [96]

Vf^2 = Vi^2 + 2ad
Vf^ = 0 + 2(-9.8)(-12)
Vf^2 = 235.2
Vf = 15.3 m/s

The correct answer is b) 15 m/s

6 0

1 year ago

Read 2 more answers

A rod of mass M and length L can rotate about a hinge at its left end and is initially at rest. A putty ball of mass m, moving w

klio [65]

Answer:

w_f = m*V*cos(Q_n) / L*(m+M)

Explanation:

Given:

- mass of the putty ball m

- mass of the rod M

- Velocity of the ball V

- Length of the rod L

- Angle the ball makes before colliding with rod Q_n

Find:

What is the angular speed ωf of the system immediately after the collision,

Solution:

- We can either use conservation of angular momentum or conservation of Energy. We will use Conservation of angular momentum of a system:

L_before = L_after

- Initially the rod is at rest, and ball is moving with the velocity V at angle Q from normal to the rod. We know that the component normal to the rod causes angular momentum. Hence,

L_before = L_ball = m*L*V*cos(Q_n)

- After colliding the ball sicks to the rod and both move together with angular speed w_f

L_after = (m+M)*L*v_f

Where, v_f = L*w_f

L_after = (m+M)*L^2 * w_f

- Now equate the two expression as per conservation of angular momentum:

m*L*V*cos(Q_n) = (m+M)*L^2 * w_f

w_f = m*V*cos(Q_n) / L*(m+M)

3 0

1 year ago