1

### 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
$90^\circ$
2

### 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
$60^\circ$
3

### 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
4

### IIT-JEE 1980

A ship of mass 3 $\times$ 107 kg initially at rest, is pulled by a force of 5 $\times$ 104 N through a distance of 3 m. Assuming that the resistance due to water is negligible, the speed of the ship is
A
1.5 m/s
B
60 m/s
C
0.1 m/s
D
5 m/s