Physics, 14.07.2019 14:00 cupcake20019peehui

Find the density of a rock that has a mass of 40 g and a volume of 20.5 cm³.

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Answer from: yuni31

Density is found by dividing mass by volume. The following formula can be used to find the density of an object:

D= $\frac{m}{v}$

D= $\frac{40 g}{20.5 cm^3}$

D=1.95 g/cm³

The density of the rock is 1.95 g/cm³.

Answer from: Quest

the unit of the measure = $\frac{j}{kgk}$

explanation:

the property that is quantified by the energy needed per of material to raise the temperature by one.

si unit of energy = joule (j)

si unit of temperature = kelvin (k)

si unit of mass of material = kilogram (kg)

the property that is quantified by the energy needed per of material to raise the temperature by one is called specific heat.

the unit of specific heat is $\frac{j}{kgk}$

Answer from: Quest

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

$f\alpha \frac{dp}{dt}$

⇒ $f= k \frac{dp}{dt}$

here k is the proportionality constant whose value is 1.

$f=\frac{dp}{dt}$

$f= \frac{d[mv]}{dt}$

$f= m\frac{dv}{dt} +v\frac{dm}{dt}$

$f=ma+v\frac{dm}{dt}$ [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.

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Find the density of a rock that has a mass of 40 g and a volume of 20.5 cm³....

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