Answer:
(a) The horizontal ground reaction force 
(b) The vertical ground reaction force 
(c) The resultant ground reaction force 
Explanation:
Given
John mass , m = 65 kg
Horizontal acceleration , 
Vertical acceleration , 
(a) Using Newton's 2nd law in horizontal direction

=>
Thus the horizontal ground reaction force 
(b) Using Newton's 2nd law in vertical direction

=>
=>
Thus the vertical ground reaction force 
(c) Resultant ground reaction force is

=>
=>
Thus the resultant ground reaction force 
More force is needed for more mass. Therefore, if the mass is greater and the force is not enough then the object will less likely accelerate
Answer:
When a dying star has a mass which is 1.4 to 3 times that of the sun, it will form a neutron star. Stars with a mass greater than thrice the sun's mass, black hole is formed.
Explanation: