Answer:
Frictional Force: Frictional force is the force caused by the relative motion of two surfaces that come into contact with each other.
Answer:
A) 37 m
Explanation:
The car is moving of uniformly accelerated motion, so the distance it covers can be calculated by using the following SUVAT equation:
(1)
where
v = 0 m/s is the final velocity of the car
u = 24 m/s is the initial velocity
a is the acceleration
d is the length of the skid
We need to find the acceleration first. We know that the force responsible for the (de)celeration is the force of friction, so:

where
m = 1000 kg is the mass of the car
is the coefficient of friction
a is the deceleration of the car
g = 9.8 m/s^2 is the acceleration due to gravity
The negative sign is due to the fact that the force of friction is against the motion of the car, so the sign of the acceleration will be negative because the car is slowing down. From this equation, we find:

And we can substitute it into eq.(1) to find d:

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
Symbolic representations are mental pictures that have no direct relationship to the actual object you are thinking about. Instead, these mental pictures are connected by themes that are meaningful to you. Anytime you think of words and descriptions for one main concept, you're thinking symbolically. Analogical representations are mental pictures that have a direct relationship to the actual object you are thinking about. Do cows have their ears on the top or side of their heads? Rather than thinking symbolically about a cow and his ears (tiny, smelly, leather), analogical representations of the cow's ears involve thinking of an actual cow in your head.