The pulley shown in figure has a radius $10cm$ and moment of inertia $0.5kg-m^2$ about its axis. Assuming the inclined planes to be frictionless, calculate the acceleration of the $4.0kg$ block.
Download our app for free and get startedPlay store


$\text{m}_1\text{g}\sin\theta-\text{T}_1=\text{m}_1\text{a}\ \dots(1)$
$(\text{T}_1-\text{T}_2)=\frac{\text{la}}{\text{r}^2}\ \dots(2)$
$\text{T}_2-\text{m}_2\text{g}\sin\theta=\text{m}_2\text{a}\ \dots(3)$
Adding the equations (1) and (3) we will get
$\text{m}_1\text{g}\sin\theta+(\text{T}_2-\text{T}_1)-\text{m}_2\text{g}\sin\theta=(\text{m}_1+\text{m}_2)\text{a}$
$\Rightarrow(\text{m}_1-\text{m}_2)\text{g}\sin\theta=\Big(\text{m}_1+\text{m}_2+\frac{1}{\text{r}^2}\Big)\text{a}$
$\Rightarrow\text{a}=\frac{(\text{m}_1-\text{m}_2)\text{g}\sin\theta}{\Big(\text{m}_1+\text{m}_2+\frac{1}{\text{r}^2}\Big)}=0.248=0.25\text{ms}^{-2}$
art

Download our app
and get started for free

Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*

Similar Questions

  • 1
    A solid disc and a ring, both of radius $10cm$ are placed on a horizontal table simultaneously, with initial angular speed equal to 10 π rad $s^{-1}$. Which of the two will start to roll earlier? The co-efficient of kinetic friction is $\mu_\text{k}=0.2$
    View Solution
  • 2
    The descending pulley shown in figure has a radius $20cm$ and moment of inertia $0.20kg-m^2$. The fixed pulley is light and the horizontal plane frictionless. Find the acceleration of the block if its mass is $1.0kg$.
    View Solution
  • 3
    Torques of equal magnitude are applied to a hollow cylinder and a solid sphere, both having the same mass and radius. The cylinder is free to rotate about its standard axis of symmetry, and the sphere is free to rotate about an axis passing through its centre. Which of the two will acquire a greater angular speed after a given time.
    View Solution
  • 4
    A non-uniform bar of weight W is suspended at rest by two strings of negligible weight as shown in. The angles made by the strings with the vertical are $36.9°$ and $53.1°$ respectively. The bar is $2m$ long. Calculate the distance d of the centre of gravity of the bar from its left end.
    View Solution
  • 5
    A body is in translational equilibrium under the action of coplanar forces. If the torque of these forces is zero about a point, is it necessary that it will also be zero about any other point?
    View Solution
  • 6
    A disc of radius R is rotating with an angular speed $\omega_\text{o}$ about a horizontal axis. It is placed on a horizontal table. The coefficient of kinetic friction is $\mu_\text{k}{:}$
    1. What was the velocity of its centre of mass before being brought in contact with the table?
    2. What happens to the linear velocity of a point on its rim when placed in contact with the table?
    3. What happens to the linear speed of the centre of mass when disc is placed in contact with the table?
    4. Which force is responsible for the effects in (b) and (c).
    5. What condition should be satisfied for rolling to begin?
    6. Calculate the time taken for the rolling to begin.
    View Solution
  • 7
    Two discs of moments of inertia $I_1$ and $I_2$ about their respective axes (normal to the disc and passing through the centre), and rotating with angular speed $\omega_1$ and $\omega_2$ are brought into contact face to face with their axes of rotation coincident.
    1. Does the law of conservation of angular momentum apply to the situation? why?
    2. Find the angular speed of the two-disc system.
    3. Calculate the loss in kinetic energy of the system in the process.
    4. Account for this loss.
    View Solution
  • 8
    Prove that the velocity v of translation of a rolling body (like a ring, disc, cylinder or sphere) at the bottom of an inclined plane of height h is given by:$\text{v}^2=\frac{2\text{gh}}{\big(1+\frac{\text{K}^2}{\text{R}^2}\big)}$
    Note K is the radius of gyration of the body about its symmetry axis, and R is the radius of the body. The body starts from rest at the top of the plane.
    View Solution
  • 9
    The structure of a water molecule is shown in figure. Find the distance of the centre of mass of the molecule from the centre of the oxygen atom.
    View Solution
  • 10
    A solid sphere of mass 0.50kg is kept on a horizontal surface. The coefficient of static friction between the surfaces in contact is $\frac{2}{7}.$ What maximum force can be applied at the highest point in the horizontal direction so that the sphere does not slip on the surface?
    View Solution