60 N because 98N=mg (here g= 9.8 on earth) thus mass can be calculated which is 98/9.8 = 10kg
Now,new weight with g = 6m/s^2
=m×g' (here g' is new acceleration of the new planet)
= 10×6=60N
when it reaches the maximum height, all the energy has now been converted into potential energy.when a ball is thrown straight upto into the air,all its initial kinetic energy converted into gravitational potential energy when it reaches its maximum height
Answer:In first case
Explanation:
When two People pull the spring, let the applied force by each person be 
and spring constant of spring be k
so Total force is 
total extension according to Hooke's law is

When they detach the spring and apply force in opposite direction then force on either side is F so net extension is

so in first case there will be more extension