Answer:
D
Explanation:
A and C are balanced, B has a resultant force of 5N right, and D has a resultant force of 20N right.
Here it is an application of Newton's III law
as we know by Newton's III law that every action has equal and opposite reaction
So here as we know that two boys jumps off the boat with different forces
from front side of the boat the boy jumps off with force 45 N which means as per Newton's III law if boy has a force of 45 N in forward direction then he must apply a reaction force on the boat in reverse direction of same magnitude
So boat must have an opposite force on front end with magnitude 45 N
Now similar way we can say
from back side of the boat the boy jumps off with force 60 N which means as per Newton's III law if boy has a force of 60 N in backward direction then he must apply a reaction force on the boat in reverse direction of same magnitude
So boat must have an opposite force on front end with magnitude 60 N
So here net force due to both jump on the boat is given by



so boat will have net force F = 15 N in forward direction due to both jumps
The meters per second
+1t a second / 2t
Answer:
(a) Bus will traveled further a distance of 40 m
(b) It will take 7.5 sec to stop the bus
Explanation:
We have given initial velocity of the bus u = 24 m/sec
And final velocity v = 16 m/sec
Distance traveled in this process s = 50 m
From third equation of motion we know that 


(a) Now as the bus finally stops so final velocity v = 0 m/sec
So 

s= 90 m
So further distance traveled by bus = 90-50 =40 m
(b) Now as the bus finally stops so final velocity v= 0 m/sec
Initial velocity u = 24 m/sec
Acceleration 
So time 