Q626
Errorless
Self Evaluation Test-Friction
MCQ
A body of mass 10 kg slides along a rough horizontal surface. The coefficient of friction is $1/\sqrt{3}$ . Taking $g = 10 \, m/s^{2}$ , the least force which acts at an angle of $30^{\circ}$ to the horizontal is
A.
25 N
B.
100 N
C.
50 N
D.
$\frac{50}{\sqrt{3}}N$
Q627
Errorless
Self Evaluation Test-Friction
MCQ
A child weighing 25 kg slides down a rope hanging from the branch of a tall tree. If the force of friction acting against him is 2 N, what is the acceleration of the child (Take $g = 9.8 \, m/s^{2}$ )
A.
$22.5 \, m/s^{2}$
B.
$8 \, m/s^{2}$
C.
$5 \, m/s^{2}$
D.
$9.72 \, m/s^{2}$
Q628
Errorless
Self Evaluation Test-Friction
MCQ
In the above question, if the lift is moving upwards with a uniform velocity, then the frictional resistance offered by the body is
A.
$Mg$
B.
$\mu Mg$
C.
$2\mu Mg$
D.
Zero
Q629
Errorless
Self Evaluation Test-Friction
MCQ
A body of mass 2 kg is moving on the ground comes to rest after some time. The coefficient of kinetic friction between the body and the ground is 0.2. The retardation in the body is
A.
$9.8 \, m/s^{2}$
B.
$4.73 \, m/s^{2}$
C.
$2.16 \, m/s^{2}$
D.
$1.96 \, m/s^{2}$