A bucket of water with a mass of 2.0 kg is attached to a rope that is wound around a cylinder. The cylinder has a mass of 4.0 kg and is mounted horizontally on frictionless bearings. The bucket is released from rest. (a) Find its speed after it has fallen through a distance of 1.50 m

Respuesta :

Answer:

The velocity of the bucket is 3.83 m/s.

Explanation:

Given that,

Mass of bucket = 2.0 kg

Mass of cylinder =4.0 kg

Distance = 1.50 m

We need to calculate the speed

Using equation of motion

[tex]v^2=u^2+2as[/tex]

Put the value into the formula

[tex]v^2=2\times a\times1.50[/tex]

[tex]v=\sqrt{2\times a\times1.50}[/tex]

We need to calculate the tension

Using equilibrium equation

[tex]mg=T+ma[/tex]

[tex]T=m(g-a)[/tex]....(I)

Put the value into the formula

[tex]T=2.0\times(9.8-a)[/tex]

Now, using formula of tension

[tex]T=I\\omega[/tex]...(II)

Moment of inertia of cylinder

[tex]I=\dfrac{1}{2}MR^2[/tex]

Angular velocity of cylinder is

[tex]\omega=\dfrac{a}{R^2}[/tex]

Put the value of angular velocity in equation (II)

[tex]T=\dfrac{1}{2}M\times(\dfrac{a}{\omega})\times\omega[/tex]

[tex]T=\dfrac{1}{2}M\times a[/tex]

Put the value of tension in equation (I)

[tex]\dfrac{1}{2}M\times a=m(g-a)[/tex]

Put the value into the formula

[tex]\dfrac{1}{2}\times4.0\times a=2.0(9.8-a)[/tex]

[tex]a=\dfrac{2.0\times9.8}{4.0}[/tex]

[tex]a=4.9\ m/s^2[/tex]

Put the value of acceleration in equation of motion

[tex]v^2=2\times4.9\times1.50[/tex]

[tex]v=\sqrt{2\times4.9\times1.50}[/tex]

[tex]v=3.83\ m/s[/tex]

Hence, The velocity of the bucket is 3.83 m/s.

Answer:

Explanation:

Given mass of bucket is [tex]m=2\ kg[/tex]

mass of cylinder [tex]M=4\ kg[/tex]

Suppose T is the tension in the rope

For bucket [tex]mg-T=ma[/tex]

where a=acceleration

For cylinder with Radius R

[tex]I\times \alpha =T\cdot R[/tex]

[tex]\frac{MR^2}{2}\times \frac{a}{R}=T\times R[/tex]

[tex]T=\frac{Ma}{2}[/tex]

[tex]a=\frac{mg}{m+0.5M}[/tex]

[tex]a=4.9\ m/s^2[/tex]

Using [tex]v^2-u^2=2a s[/tex] for bucket

v=final velocity

u=initial velocity

s=displacement

[tex]v^2-0=2\times 4.9\times 1.5[/tex]

[tex]v=\sqrt{14.7}[/tex]

[tex]v=3.83\ m/s[/tex]