A planet has the mass same as the earth but its radius is twice of the earth's radius. On that planet, a ball of mass 3.4 kg is thrown upward with velocity 15 m/s. What will be the height of the object 2 second before reaching its maximum height? (Take acceleration due togravity on earth 'g' as 10 m/s²)
Answers
Answer:
Hence, the answer is 5m/s
2
Step-by-step explanation:
q
′
=
R
2
GM
=
(4ve)
2
G×2me
=
8
1
ve
2
Gme
=
8
g
To find 4 times the acceleration due to gravity =4×
8
1
g=
2
g
=
2
10
=5m/s
2
Hence, the answer is 5m/s
2
.
Given:
Planet :
mass of planet = mass of earth
radius of planet = 2x radius of earth
On that planet, a ball of mass 3.4 kg is thrown upward with velocity 15 m/s.
To Find:
What will be the height of the object 2 second before reaching its maximum height?
Solution:
first we have to find the gravity on planet.
it is given by g=Gm/R²
as the radius is twice of the radius of the earth,
g = Gm/(2r)²
=Gm/4r²
and we know that Gm/r² = 10m/s²
therefore g on planet = 10/4=2.5m/s²
according to the question,
for maximum height, final velocity , v= 0
applying equation of motion v=u+at
0= 15 - 2.5t
t=6 sec
so we have to find the height at 4 sec,
S= ut + 0.5at²
=15x4 - 0.5x2.5x4²
=60 - 0.5x2.5x16
=60-20
=40 m
Hence the height of the object 2 second before reaching its maximum height is 40 m.