A body is coming with a velocity of 72 km/h on a rough horizontal surface of coefficient of friction 0.5. If the acceleration due to gravity is , find the minimum distance it can be stopped.
Block pressed against wall by force . Find incorrect statement.
1
friction force = mg
2
3
does not apply torque
4
does not apply torque
Official Solution
Correct Option: (4)
Concept:
Torque depends on line of action of force. Step 1: Check forces
Normal force acts at wall can produce torque Step 2: Incorrect statement
Saying produces no torque is wrong Conclusion: (D)
03
PYQ 2014
medium
physicsID: met-2014
A body rests on smooth surface. Body placed over has coefficient of friction . Find force required to just move .
1
2
3
4
It will not slide
Official Solution
Correct Option: (1)
Concept:
Maximum static friction:
Step 1: Normal force
Step 2: Maximum friction
Step 3: System acceleration
Total mass For limiting condition:
But effective force acting only on :
Conclusion:
04
PYQ 2015
medium
physicsID: met-2015
A block of mass is lying on the edge having inclination angle . Wedge is moving with a constant acceleration ms . The minimum value of coefficient of friction , so that remains stationary with respect to wedge is
1
2
3
4
Official Solution
Correct Option: (2)
Step 1: Understanding the Concept:
\begin{itemize}
\item In non-inertial frame of wedge:
\begin{itemize}
\item Pseudo-force acts horizontally backward on block
\end{itemize}
\end{itemize} Step 2: Detailed Explanation:
\begin{itemize}
\item Normal reaction:
\item Friction:
\item Therefore:
\item Simplifying:
\item Substituting values:
\end{itemize} Step 3: Final Answer:
Minimum coefficient of friction .
