Kinematics Question 397
Question: The ball is projected up from ground with speed $ 30m/sec $ . What is the average velocity for time 0 to 4 sec?
Options:
A) $ 10m/sec $
B) $ 20m/sec $
C) $ \text{15 }m/sec $
D) $ zero $
Show Answer
Answer:
Correct Answer: A
Solution:
We should know the displacement in this time.
$ \vec{v} = \overrightarrow{u}t + \frac{1}{2}\overrightarrow{a}t^{2} $
(We take upward as positive)
$ S=30\times 4-10\times 4\times \frac{4}{2}=80\text{ m}\text{.} $
The average velocity will be $ 10m/sec $ .
BETA
