A stone is thrown in a vertically
upward direction with a velocity of 5 ms^-1 . If the acceleration of the
stone during its motion is 10 ms^-1 in the downward direction, what will be the height attained by the
stone and how much time will it
take to reach there?
Answers
Answer:
MARK BRAINLIEST OR I REPORT QUESTION
Explanation:
Given, initial velocity, u=5ms−1
Final velocity, v=0
Since, u is upward & a is downward, it is a retarded motion.
∴a=−10ms−2
Height attained by stone, s=?
Time take to attain height, t=?
(i) Using the relation, v2−u2=2as, we have
s=v2−u2/2a
=(0)2−(5)2/2×(−10)=1.25m
(ii) Using the relation, v=u+at
0=5+(−10)t or
t=5/10=0.5s
Figure regards this question:
- Kindly go to web for the diagram.
Provided that:
- Initial velocity = 5 m/s
- Final velocity = 0 m/s
- Acceleration = -10 m/s²
Don't be confused!
⋆ Final velocity cames as zero because when it is thrown upwards then it will be stopped at the highest point.
⋆ We write acceleration in negative except of positive because the object is thrown in upward direction.
To calculate:
- Height attained by stone
- Time taken
Solution:
- Height attain by stone = 1.25 m
- Time taken = 0.5 second
Using concepts:
- Newton's first law of motion
- Newton's third law of motion
Using formulas:
• Newton's first law of motion is given by the mentioned formula:
• Newton's third law of motion is given by the mentioned formula:
Where, v denotes final velocity, u denotes initial velocity, a denotes acceleration, t denotes time taken, s denotes displacement or distance or height.
Required solution:
~ Firstly let us find out the time taken!
→ v = u + at
→ 0 = 5 + (-10)(t)
→ 0 = 5 + (-10t)
→ 0 - 5 = -10t
→ -5 = -10t
→ 5 = 10 t
→ 5/10 = t
→ 0.5 = t
→ t = 0.5 seconds
→ Time = 0.5 seconds
~ Now let's calculate height!
→ v² - u² = 2as
→ (0)² - (5)² = 2(-10)(s)
→ 0 - 25 = (-20s)
→ -25 = -20s
→ 25 = 20s
→ 25/20 = s
→ 5/4 = s
→ 1.25 = s
→ s = 1.25 metres
→ Distance = 1.25 metres