Laws of Motion Physics - Laws of Motion

• A
  The impulse imparted to each ball is $0.25\ kg m s^{–1}$ and the force on each ball is $250N.$
• B
  The impulse and the force on each ball are equal in magnitude and opposite in direction.
• C
  The impulse imparted to each ball is $0.5Ns.$
• ✓
  Both $B$ and $C$

Answer: D.

• A
  $1ms^{–2}$ at an angle of $14 \tan^{-1}\Big(\frac{4}{3}\Big)$ w.r.t. $6N$ force.
• B
  $0.2ms^{–2}$ at an angle of $\tan^{-1}\Big(\frac{4}{3}\Big)$ w.r.t. $6N$ force.
• C
  $1ms^{–2}$ at an angle of $\tan^{-1}\Big(\frac{4}{3}\Big)$ w.r.t. $8N$ force.
• ✓
  Both $A$ and $C$

Answer: D.

• A
  The force acting on the scale is zero, but a torque about the centre of mass can act on the scale.
• ✓
  The force acting on the scale is zero and the torque acting about centre of mass of the scale is also zero.
• C
  The total force acting on it need not be zero but the torque on it is zero.
• D
  Neither the force nor the torque need to be zero.

Answer: B.

• A
  It is at rest.
• B
  The path can be a straight line or circular and the ball travels with uniform speed.
• ✓
  All parts of the ball have the same velocity (magnitude and direction) and the velocity is constant.
• D
  The centre of the ball moves with constant velocity and the ball spins about its centre uniformly.

Answer: C.

• A
  Zero
• B
  $0.75 \mathrm{~kg} \mathrm{~m} \mathrm{~s}^{-1}$
• ✓
  $1.5 \mathrm{~kg} \mathrm{~m} \mathrm{~s}^{-1}$
• D
  $14 \mathrm{~kg} \mathrm{~m} \mathrm{~s}^{-1}$

Answer: C.