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3 years ago

What is the definition of cell ?

1 answer:

5 0

the smallest structural and functional unit of an organism, typically microscopic and consisting of cytoplasm and a nucleus enclosed in a membrane. Microscopic organisms typically consist of a single cell, which is either eukaryotic or prokaryotic.

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Which measurements are equal to 321 decimeters? Check all that apply.

S_A_V [24]

32,100 Millimeters
3,210 Centimeters
3.21 Decameters

Hope It Helps

5 0

4 years ago

Read 2 more answers

True/False: Paraphrasing Einstein’s Theory of General Relativity, gravity "handprint" makes an "indentation" in the fabric of sp

Y_Kistochka [10]

B.False

Einstein's vision of GR is NOT that somehow Gravity comes along and alters (indents?) some existing structure.
It is that Gravity (with its four possible sources) actually determines the entire global structure of Space-Time in which such sources are extant.

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3 years ago

How can the rate of a reaction be increased?

olya-2409 [2.1K]

<h3>Answer and explanation;</h3>

-Rate of reaction is the speed at which the reactants are converted to products.

-Rate of reactions depends on a number of factors which includes;

Concentration of reactants; increasing the concentration of reactants increases the rate of reaction.
Temperature; An increase in temperature results to an increased rate of reaction. Increase in temperature increases the kinetic energy of molecules thus the collision per unit time also increases and hence the rate of reaction increases.
Decreasing the size of particles of solid reactants also increases the rate of reaction. This is because smaller particles increases the surface area on which more collisions can occur thus a faster rate of reaction.
Adding a catalyst also increases the rate of reaction. This is because catalysts lower the activation energy of reactants, minimum energy require by reactants for the reaction to take place. This thus increases the rate of reaction.

5 0

4 years ago

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What statement BEST describes a solid?

BARSIC [14]

Solids: definite shape, definite volume
Because they are stiff and the molecules don't move around, they vibrate quickly.
Liquids: indefinite shape, definite volume
Because the shape or "fixed" area of liquids won't stay the same.
Gases: indefinite shape, indefinite volume
Because you've probably noticed, gases are set more freely, allowing molecules to move more freely than in solids and liquids.
x) Hope I helped! Which do you think it is?

5 0

3 years ago

Read 2 more answers

A boy kicks a football from ground level. The ball takes 3 seconds to reach its maximum height. What is the angle of the initial

ruslelena [56]

<h2>The angle of the initial velocity with respect to the horizontal is 85.14°</h2>

Explanation:

Given that the ball takes 3 seconds to reach its maximum height.

Consider the vertical motion of ball till maximum height.

We have equation of motion v = u + at

Acceleration, a = -9.81 m/s²

Final velocity, v = 0 m/s

Time, t = 3 s

Substituting

v = u + at

0 = u + -9.81 x 3

u = 29.43 m/s

Initial vertical velocity is 29.43 m/s.

Now consider horizontal motion of ball.

Time of flight of ball = 2 x Time to reach maximum height = 2 x 3 = 6 s

Displacement = 15 m

We have equation of motion s = ut + 0.5 at²

Displacement, s = 15 m

Acceleration, a = 0 m/s²

Time, t = 6 s

Substituting

s = ut + 0.5 at²

15 = u x 6 + 0.5 x 0 x 6²

u = 2.5 m/s

Initial horizontal velocity is 2.5 m/s

Let r be the initial velocity and θ be the angle with horizontal

Initial vertical velocity = rsinθ = 29.43 m/s

Initial horizontal velocity = rcosθ = 2.5 m/s

Dividing

$\frac{rsin\theta }{rcos\theta }=\frac{29.43}{2.5}\\\\tan\theta=11.77\\\\\theta=85.14^0$

The angle of the initial velocity with respect to the horizontal is 85.14°

4 0

3 years ago