1

### IIT-JEE 2009

A block of base 10 cm × 10 cm and height 15 cm is kept on an inclined plane. The coefficient of friction between them is $\sqrt 3$. The inclination θ of this inclined plane from the horizontal plane is gradually increased from $0^\circ$. Then
A
at θ = $60^\circ$, the block will start sliding down the plane
B
the block will remain at rest on the plane up to certain θ and then it will topple
C
at θ = $60^\circ$, the block will start sliding down the plane and continue to do so at higher angles
D
at θ = $60^\circ$, the block will start sliding down the plane and on further increasing θ, it will topple at certain θ
2

### IIT-JEE 2007

A particle moves in the X - Y plane under the influence of a force such that its linear momentum is $\overrightarrow p \left( t \right) = A\left[ {\widehat i\cos (kt) - \widehat j\sin (kt)} \right]$, where A and k are constants. The angle between the force and the momentum is
A
$0^\circ$
B
$30^\circ$
C
$45^\circ$
D
$90^\circ$
3

### IIT-JEE 2001 Screening

The pulleys and strings shown in the figure are smooth and of negligible mass. For the system to remain in equilibrium, the angle $\theta$ should be
A
$0^\circ$
B
$30^\circ$
C
$45^\circ$
D
$60^\circ$
4

### IIT-JEE 1994

A block of mass 0.1 is held against a wall applying a horizontal force of 5 N on the block. If the coefficient of friction between the block and the wall is 0.5, the magnitude of the frictional force acting on the block is:
A
2.5 N
B
0.98 N
C
4.9 N
D
0.49 N