Which are two of Jupiter’s moons? Europa and Io Sirius and Polaris Galileo and Voyager Pluto and Neptune

A solid, uniform disk of radius 0.250 m and mass 45.2 kg rolls down a ramp of length 5.40 m that makes an angle of 17.0° with th

serious [3.7K]

Explanation:

Given that,

Radius of the disk, r = 0.25 m

Mass, m = 45.2 kg

Length of the ramp, l = 5.4 m

Angle made by the ramp with horizontal, $\theta=17^{\circ}$

Solution,

As the disk starts from rest from the top of the ramp, the potential energy is equal to the sum of translational kinetic energy and the rotational kinetic energy or by using the law of conservation of energy as :

(a) $mgh=\dfrac{1}{2}mv^2+\dfrac{1}{2}I\omega^2$

h is the height of the ramp

$sin\theta=\dfrac{h}{5.4}$

$h=sin(17)\times 5.4=1.57\ m$

v is the speed of the disk's center

I is the moment of inertia of the disk,

$I=\dfrac{1}{2}mr^2$

$\omega=\dfrac{v}{r}$

$mgh=\dfrac{1}{2}mv^2+\dfrac{1}{2}\dfrac{1}{2}mr^2\times (\dfrac{v}{r})^2$

$gh=\dfrac{1}{2}v^2+\dfrac{1}{4}v^2$

$gh=\dfrac{3}{4}v^2$

$9.8\times 1.57=\dfrac{3}{4}v^2$

v = 4.52 m/s

(b) At the bottom of the ramp, the angular speed of the disk is given by :

$\omega=\dfrac{v}{r}$

$\omega=\dfrac{4.52}{0.25}$

$\omega=18.08\ rad/s$

Hence, this is the required solution.

4 0

4 years ago

The energy transferred between objects in contact as of temperature difference is called what?

slamgirl [31]

Answer:

Heat

Explanation:

4 0

3 years ago

Read 2 more answers

Why is it important to always subtract the earlier value from the later value when finding the change in mass,instead of always

Artist 52 [7]

Mass and energy are inter convertible.As per Einsteins mass and energy relations i.e $E=Mc^2$ ,some amount of energy is lost that is converted into energy .

In our day to day life ,generally mass is lost and energy is formed. In a ideal assumption we subtract the mass of earlier one from the later one which indirectly denotes that some amount of mass is lost and energy is released .There is also endothermic reactions where energy is needed which does not mean mass is added.Here simply energy is needed to initiate the reactions.

So instead of subtracting the smaller value from lager we subtract the initial value from final as the latter one can explain a physical phenomenon in a better way.we can get some in formation from it.

3 0

3 years ago

The ______ clause in an if statement allows a program to make one choice if the condition is true, and anothere choice if the co

Inessa [10]

Answer: The IF clause.

Explanation: This is the IF clause; you can use it as:

IF (something = true) then "something happens"

else "other thing happens"

Some example of it can be, suppose that your program reads a number X that the user inputs, then you can do:

If ( X > 5) then

print: "the number X is bigger than five"

Else

print: "the number X is smaller than five"

Where, of course, the statements depend on the language used, but the "if" clause works almost the same in every language.

3 0

3 years ago

Can someone help me?!!!!!

igor_vitrenko [27]

Answer:

7 units, north

Explanation:

This is a problem of vector subtraction. We have:

- Vector A: magnitude 2 units, direction to the north

- Vector B: magnitude 5 units, direction to the south

If we take the north as positive direction, we can write

$A = +2\\B=-5$

Since we want to find $A-B$ (vector subtraction), we have to change the sign of B, so we find:

$A-B=+2-(-5))=+2+5=+7$

And the positive sign means the direction is north.

6 0

3 years ago