Answer
77.7k+ views
Hint: To find how fast will the child be going at the bottom of the slide, we can compare the height of the slide with kinetic energy.
Complete step by step answer:
The child is moving at the bottom of the slide. By using conservation of energy we have,
At the top of the slide, the child has all gravitational potential energy, given by
${U_i} = mgh$
where \[m\] is the mass of the child
$g = 9.8m/{s^2}$
The height of the slide is given by
$h = L\sin 45^\circ $
At the bottom of the slide, all of that energy will have been converted to kinetic energy:
$K_f = \dfrac{1}{2}M{V^2}$
we aren't losing any energy to friction, we must have
$\Rightarrow Mg L\sin 45^\circ = \dfrac{1}{2}M{V^2}$
$\Rightarrow L = 3.2$
By solving the above equation we can get the velocity as
\[\Rightarrow v{\text{ }} = {\text{ }}6.7{\text{ }}m/s\] .
Additional information:
Kinetic energy is directly proportional to the mass of the object and the square of its velocity:
$KE = \dfrac{1}{2}M{V^2}$
If the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared.
It is the energy that an object possesses because of its motion. Kinetic energy is dependent on the velocity of the object squared. And this energy should be either a zero or a negative value.
Note: This kinetic energy refers to the work required to accelerate the body of a particular mass from a state of rest to its stated velocity. The standard unit of this kinetic energy happens to be the joule.
Complete step by step answer:
The child is moving at the bottom of the slide. By using conservation of energy we have,
At the top of the slide, the child has all gravitational potential energy, given by
${U_i} = mgh$
where \[m\] is the mass of the child
$g = 9.8m/{s^2}$
The height of the slide is given by
$h = L\sin 45^\circ $
At the bottom of the slide, all of that energy will have been converted to kinetic energy:
$K_f = \dfrac{1}{2}M{V^2}$
we aren't losing any energy to friction, we must have
$\Rightarrow Mg L\sin 45^\circ = \dfrac{1}{2}M{V^2}$
$\Rightarrow L = 3.2$
By solving the above equation we can get the velocity as
\[\Rightarrow v{\text{ }} = {\text{ }}6.7{\text{ }}m/s\] .
Additional information:
Kinetic energy is directly proportional to the mass of the object and the square of its velocity:
$KE = \dfrac{1}{2}M{V^2}$
If the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared.
It is the energy that an object possesses because of its motion. Kinetic energy is dependent on the velocity of the object squared. And this energy should be either a zero or a negative value.
Note: This kinetic energy refers to the work required to accelerate the body of a particular mass from a state of rest to its stated velocity. The standard unit of this kinetic energy happens to be the joule.
Recently Updated Pages
Name the scale on which the destructive energy of an class 11 physics JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Write an article on the need and importance of sports class 10 english JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Choose the exact meaning of the given idiomphrase The class 9 english JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Choose the one which best expresses the meaning of class 9 english JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
What does a hydrometer consist of A A cylindrical stem class 9 physics JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
A motorcyclist of mass m is to negotiate a curve of class 9 physics JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)