AnswerNo
However, the acceleration is the opposite of the movement:
Explanation:
The impulse required to decrease the speed of the boat is equal to the variation of momentum of the boat:

where
m=225 kg is the mass of the boat

is the variation of velocity of the boat
By substituting the numbers into the first equation, we find the impulse:

and the negative sign means the direction of the impulse is against the direction of motion of the boat.
Answer:
a 200 feet, and trains go a whole mile even after hitting the brakes
Explanation:
Answer:
k1 + k2
Explanation:
Spring 1 has spring constant k1
Spring 2 has spring constant k2
After being applied by the same force, it is clearly mentioned that spring are extended by the same amount i.e. extension of spring 1 is equal to extension of spring 2.
x1 = x2
Since the force exerted to each spring might be different, let's assume F1 for spring 1 and F2 for spring 2. Hence the equations of spring constant for both springs are
k1 = F1/x -> F1 =k1*x
k2 = F2/x -> F2 =k2*x
While F = F1 + F2
Substitute equation of F1 and F2 into the equation of sum of forces
F = F1 + F2
F = k1*x + k2*x
= x(k1 + k2)
Note that this is applicable because both spring have the same extension of x (I repeat, EXTENTION, not length of the spring)
Considering the general equation of spring forces (Hooke's Law) F = kx,
The effective spring constant for the system is k1 + k2
When the body touches the ground two types of Forces will be generated. The Force product of the weight and the Normal Force. This is basically explained in Newton's third law in which we have that for every action there must also be a reaction. If the Force of the weight is pointing towards the earth, the reaction Force of the block will be opposite, that is, upwards and will be equivalent to its weight:
F = mg
Where,
m = mass
g = Gravitational acceleration
F = 5*9.8
F = 49N
Therefore the correct answer is E.