True or false around 250 million year ago, all the continents were joined in one landmass, called Cambria

How do its eight arms help an octopus obtain food

Andrews [41]

The more arms it has the less of a chance the prey has to swim away.

5 0

3 years ago

When a man stands on a bathroom scale here on Earth, it reads 640 N . Assume each planet to be a perfect sphere with the followi

noname [10]

Answer:

242.19702 N

578.46718 N

681.02785 N

Explanation:

M = Mass of the corresponding planet

r = Radius of the corresponding planet

g = Acceleration due to gravity = 9.81 m/s²

G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²

Mass of person

$m=\frac{W}{g}\\\Rightarrow m=\frac{640}{9.81}=65.23955\ kg$

Mass is the property of an object, it is constant irrespective of the forces acting on it so the mass of the person on each planet would be the same.

Gravitational force on Mars

$F=\frac{GMm}{r^2}\\\Rightarrow F=\frac{6.67\times 10^{-11}\times 6.419\times 10^{23}\times 65.23955}{(3.396\times 10^{6})^2}\\\Rightarrow F=242.19702\ N$

Magnitude of the gravitational force Mars would exert on the man if he stood on its surface is 242.19702 N

Gravitational force on Venus

$F=\frac{GMm}{r^2}\\\Rightarrow F=\frac{6.67\times 10^{-11}\times 4.869\times 10^{24}\times 65.23955}{(6.052\times 10^{6})^2}\\\Rightarrow F=578.46718\ N$

Magnitude of the gravitational force Venus would exert on the man if he stood on its surface is 578.46718 N

Gravitational force on Saturn

$F=\frac{GMm}{r^2}\\\Rightarrow F=\frac{6.67\times 10^{-11}\times 5.685\times 10^{26}\times 65.23955}{(6.027\times 10^{7})^2}\\\Rightarrow F=681.02785\ N$

Magnitude of the gravitational force Saturn would exert on the man if he stood on its surface is 681.02785 N

6 0

4 years ago

What does the slope of the curve on a distance vs time graph represent?

Lilit [14]

Slope of a curve Y plotted against X is mathematically given as

$slope = \frac{dy}{dx}$

now here we can see that if similarly graph is plotted against distance and time then slope is given as

$slope = \frac{dx}{dt}$

here we can say that above is ratio of small distance and very small interval of time.

so here we can say that this ratio of distance and time for very small interval of time is known as instantaneous speed of the object which is falling freely under gravity.

So here slope of the graph will represent the speed at a given instant.

6 0

3 years ago

Calculate [H3O+ ] of a 0.150 M acetic acid solution.

Butoxors [25]

Answer:

[H3O+] = 0.00520 M

Explanation:

The dissociation of acetic acid in water is given by the equation;

CH3COOH + H2O<-------> H3O+ + CH3COO-

ka = [H+][C2H3O2-]/[HC2H3O2]

Ka = 1.8 x 10^-5

= x^2 / 0.150-x

x = [H3O+]= 0.00520 M

6 0

4 years ago

A block of mass 5 kg is placed on a rough table having a coefficient of static friction μs = 0.2.What is the force required to m

just olya [345]

Answer:

We need to (at least) apply a force of 9.8 N to move the block

Explanation:

Second Newton's Law

If a net force $F_n$ different from zero is applied to an object of mass m, then it will move at an acceleration a, given by

$F_n=ma$

If we apply a force F to an object placed on a rough surface, the only way to make it move is to beat the friction force which is given by

$F_r=\mu F_N$

Where $\mu$ is the static friction coefficient and $F_N$ is the normal force exerted by the table to the object. Since there is no motion in the vertical direction the normal force equals the weight of the object:

$F_N=mg=5\ kg\ 9.8\ m/s^2=49\ N$

The friction force is

$F_r=0.2 (49)=9.8\ N$

Thus, we need to (at least) apply a force of 9.8 N to move the block

5 0

4 years ago