Which of the following is true about natural selection?

When it comes to sedimentary rocks, why is it important compaction occurs before cementation? How would cementation be affected

Salsk061 [2.6K]

Answer:

Clastic sedimentary rocks are made of pieces of rock or mineral grains that have been broken from preexisting rock. These particles and grains have become solid rock by the processes of compaction or cementation of sediments.

When these crystals grow large enough to fill the spaces they harden and form a solid rock.

7 0

3 years ago

what is the efficiency of a machine that can carry a load of 100 kg with an effort of 20N when its velicity ratio is 10 ASAP

Salsk061 [2.6K]

Answer:

Efficiency of machine=4.9

Explanation:

We are given that

Mass of load=100 kg

Effort=20 N

Velocity ratio=10

We have to find the efficiency of machine.

Load= $mg=100\times 9.8=980 N$

Efficiency= $\frac{Load}{effort}\times \frac{1}{velocity\;ratio}$

Using the formula

Efficiency of machine= $\frac{980}{20}\times \frac{1}{10}$

Efficiency of machine= $\frac{49}{10}$

Efficiency of machine=4.9

7 0

4 years ago

A hydraulic press must exert a force of 20,000N to crush a wrecked car into a convienent block. If the output piston is eight ti

Brilliant_brown [7]

Answer:

Explanation:

We shall apply Pascal's law here to find the solution .According to this law if we apply a pressure on a particular area over an in-compressible liquid it gets transferred to other point inside or over the surface of the liquid without getting diminished.

in the present case force is applied on a car to crush it which is enormous in magnitude. This force is 20000 N, which is also called output force Let the surface on which car is placed be A₂. We apply input force F₁ at other point over a small area be it A₁.

According to Pascal law ,

20000/ A₂ = F₁ / A₁

F₁ = 20000 X (A₁ / A₂)

= 20000 X 1/8

= 2500 N.

3 0

3 years ago

What property appplies to the element radon?

Arlecino [84]

Radioactive element
I. E..,ratio of neutrons is to protons is greater than 1.5

8 0

3 years ago

A rifle bullet with mass 8.00g strikes and embeds itself in a block with mass 0.992kg that rests on a frictionless, horizontal s

mafiozo [28]

Answer:

block velocity v = 0.09186 = 9.18 10⁻² m/s and speed bollet v₀ = 11.5 m / s

Explanation:

We will solve this problem using the concepts of the moment, let's try a system formed by the two bodies, the bullet and the block; In this system all scaffolds during the crash are internal, consequently, the moment is preserved.

Let's write the moment in two moments before the crash and after the crash, let's call the mass of the bullet (m) and the mass of the Block (M)

Before the crash

p₀ = m v₀ + 0

After the crash

$p_{f}$ = (m + M) v

p₀ = $p_{f}$

m v₀ = (m + M) v (1)

Now let's lock after the two bodies are joined, in this case the mechanical energy is conserved, write it in two moments after the crash and when you have the maximum compression of the spring

Initial

Em₀ = K = ½ m v2

Final

E $m_{f}$ = Ke = ½ k x2

Emo = E $m_{f}$

½ m v² = ½ k x²

v² = k/m x²

Let's look for the spring constant (k), with Hook's law

F = -k x

k = -F / x

k = - 0.75 / -0.25

k = 3 N / m

Let's calculate the speed

v = √(k/m) x

v = √ (3/8.00) 0.15

v = 0.09186 = 9.18 10⁻² m/s

This is the spped of the block plus bullet rsystem right after the crash

We substitute calculate in equation (1)

m v₀ = (m + M) v

v₀ = v (m + M) / m

v₀ = 0.09186 (0.008 + 0.992) /0.008

v₀ = 11.5 m / s

6 0

3 years ago