All categories

3 years ago

What is the cause of the plate tectonic activity?

1 answer:

5 0

Convection of liquid in the metal core,
Evidence from safari to explain:
heat from the Earth's interior causes currents of hot rising magma and cooler sinking magma to flow, moving the plates of the crust along with them.

You might be interested in

Danny sails a boat downstream. The wind pushes the boat along at 21 km/hr. The current runs downstream at 15 km/hr. What is the

abruzzese [7]

Answer:

36 km/h

Explanation:

The total velocity is the sum of the two velocities that add to the movement of the boat.

Since the wind pushes the boat at 21 km/h and the current that runs in the direction of the movent of the boat is 15 km/h, the total velocity at wich the boat moves is:

21km/h + 15 km/h = 36 km/h

3 0

3 years ago

Calculate the efficiency of a machine if the input work is 200J and the output work is 150J.

lidiya [134]

Answer:

75% is the efficency of this maxhine

8 0

3 years ago

Ron bicycles forward with an acceleration of 2.1 m/s2. If he is applying a forward force

Mila [183]

Answer:

195

Explanation:

he can only apply as much force as his body mass so it would be 195

3 0

3 years ago

A cylindrically shaped piece of collagen (a substance found in the body in connective tissue) is being stretched by a force that

Marat540 [252]

Answer:

Part(a): The value of the spring constant is $3.11 \times 10^{2}~Kg~s^{-2}$ .

Part(b): The work done by the variable force that stretches the collagen is $1.5 \times 10^{-6}~J$ .

Explanation:

Part(a):

If ' $k$ ' be the force constant and if due the application of a force ' $F$ ' on the collagen ' $\Delta l$ ' be it's increase in length, then from Hook's law

$F = k~\Delta l....................................................................(I)$

Also, Young's modulus of a material is given by

$Y = \dfrac{F/A}{\Delta l/l}...............................................................(II)$

where ' $A$ ' is the area of the material and ' $l$ ' is the length.

Comparing equation ( $I$ ) and ( $II$ ) we can write

$&& Y = \dfrac{l~k}{A}\\&or,& k = \dfrac{Y~A}{l}\\&or,& k = \dfrac{Y~(\pi~r^{2})}{l}$

Here, we have to consider only the circular surface of the collagen as force is applied only perpendicular to this surface.

Substituting the given values in equation ( $III$ ), we have

$k = \dfrac{3.10 \times 10^{6}~N~m^{-2} \times \pi \times (0.00093)^{2}~m^{2}}{.027~m} = 3.11 \times 10^{2}~Kg~s^{-2}$

Part(b):

We know the amount of work done ( $W$ ) on the collagen is stored as a potential energy ( $U$ ) within it. Now, the amount of work done by the variable force that stretches the collagen can be written as