Question

two balls are dropped tothe ground from different heights .one ball is dropped 2s after the other but they both strike the ground at the same time, 5 sec after the first was dropped .the difference in the heights at which they were dropped is..?

Answer 1

Given First Ball hit Ground in=5 seconds
when dropped .

Difference between First and second Ball=2 seconds when dropped

Second Ball will hit Ground at=5-2=3 seconds

Now Let First Fall Dropped From Height=S1
Intial Velocity (u)=0 m/s in hands
Time(t)=5 seconds
Accerlation due to Gravity (a)=10 m/s²
Use Equation of Motion
=S=ut+1/2×a×t²
S1=0×5+1/2×10×5²
S1=5×5²
S1=125 m

Now Let Second Ball Dropped from height=S2
Intial Velocity (u)=0 m/s
Time(t)=3 seconds
Accerlation due to Gravity (a)=10 m/s
Then
S2=0×3+1/2×10×3²
=5×3²
S2=45m

Difference=S1-S2
=125-45
=80 m
Difference Between height
=80 m