wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

A body is freely falling under the action of gravity. It covers half the total distance in the last second of its fall. If it falls for n second, then the value of n is

A
2
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
2+2
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
2
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
22
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B 2+2
Let h be the total distance covered in n second then,
for free fall h=12gn2
As per the question, distance covered by it in last second i.e. (n1)th sec is given by
h=h2=12gn22=14gn2
Thus, we have
12g(n1)2=14gn2
Solving above equation we get a quadratic equation in n as
n24n+2=0
n=(4)±(4)24×22
n=4±222=2±2
Now, n1>0 if n=22
(22)1>0 12<0
Hence, the value of n is 2+2.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Motion Under Gravity
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon