Kinematics Question 449
Question: A metal sphere it’s hung by a string fixed to a wall. The sphere it’s pushed away from the wall by a stick. The forces acting on the sphere are shown in the second diagram. Which of the following statements it’s wrong?
Options:
A) $ P=W\tan \theta $
B) $ \vec{T}+\vec{P}+\vec{W}=0 $
C) $ T^{2}=P^{2}+W^{2} $
D) $ T=P+W $
Show Answer
Answer:
Correct Answer: C
Solution:
[c] As the metal sphere it’s in equilibrium under the effect of the three forces therefore
$ \overrightarrow{T}+\overrightarrow{P}+\overrightarrow{W}=0 $
$ T\cos \theta =W $ …(i)
$ T\sin \theta =P $ …(ii)
From equation (i) and (ii) we get
$ P=W\tan \theta $ and $ T^{2}=P^{2}+W^{2} $
BETA
