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4 years ago

7

A van travels 24 km with a constant speed of 65 km/h and another 50 km with a constant speed of 80 km/h. How long did it take fo

r this trip?

1 answer:

Bess [88]4 years ago

7 0

I don't know the answer to that

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Objects 1 and 2 attract each other with a gravitational force of 12 units. If the mass of Object 2 is tripled, then the new grav

olasank [31]

Explanation:

Fgravity = G*(mass1*mass2)/D².

G is the gravitational constant, which has the same value throughout our universe.

D is the distance between the objects.

so, if you triple one of the masses, what does that do to our equation ?

Fgravitynew = G*(3*mass1*mass2)/D²

due to the commutative property of multiplication

Fgravitynew = 3* G*(mass1*mass2)/D² = 3* Fgravity

so, the right answer is 3×12 = 36 units.

5 0

2 years ago

You are given a sample of metal and asked to determine its specific heat. You weigh the sample and find that its weight is 27.2

garri49 [273]

Answer:

c=326.5177 J/kg.K

Specific heat is c=326.5177 J/kg.K

Explanation:

In order ti find the specific heat, we will proceed as follow:

Formula we are going to use is:

$Q=m*c*\Delta T$

Where:

Q is the heat energy added

m is the mass of sample

c is the specific heat

$\Delta T$ is the temperature Rise.

First we will find the mass:

Weight=m*g (g is gravitational acceleration=9.8 m/s^2)

$m=\frac{weight}{g} \\m=\frac{27.2}{9.8} \\m=2.7755 \ kg$

Rearranging above formula:

$c=\frac{Q}{m* \Delta T}$

$c=\frac{1.45*10^4}{2.7755*16}$

c=326.5177 J/kg.K

Specific heat is c=326.5177 J/kg.K

5 0

3 years ago

Maria drove 100 miles in 2 hrs. what was marias speed?

puteri [66]

50 miles per hour was Maria’s speed

8 0

2 years ago

Read 2 more answers

Identify the law that describes how rock layers settle over time

Lynna [10]

This is the Law of Horizontality

5 0

3 years ago

How would a spinning disk's kinetic energy change if its moment of inertia was five times larger but its angular speed was five

Keith_Richards [23]

Answer:

<em>The kinetic energy of a spinning disk will be reduced to a tenth of its initial kinetic energy if its moment of inertia is made five times larger, but its angular speed is made five times smaller.</em>

<em></em>

Explanation:

Let us first consider the initial characteristics of the angular motion of the disk

moment of inertia = $I$

angular speed = ω

For the second case, we consider the characteristics to now be

moment of inertia = $5I$ (five times larger)

angular speed = ω/5 (five times smaller)

Recall that the kinetic energy of a spinning body is given as

$KE = \frac{1}{2}Iw^{2}$

therefore,

for the first case, the K.E. is given as

$KE = \frac{1}{2}Iw^{2}$

and for the second case, the K.E. is given as

$KE = \frac{1}{2}(5I)(\frac{w}{5} )^{2} = \frac{5}{50}Iw^{2}$

$KE = \frac{1}{10}Iw^{2}$

<em>this is one-tenth the kinetic energy before its spinning characteristics were changed.</em>

<em>This implies that the kinetic energy of the spinning disk will be reduced to a tenth of its initial kinetic energy if its moment of inertia is made five times larger, but its angular speed is made five times smaller.</em>

6 0

3 years ago