Answer:
Newton's Second Law of Motion
Explanation:
According to Newton's second law of motion, the change in velocity of a body is directly proportional to the force applied on it. Velocity is a vector quantity. It measures the magnitude of the speed as well as its direction.
F = m a
where, F is the applied force, m is the mass and a is the acceleration.
It can also be expressed as:

where, p = mv ( momentum)
This phenomenon can be describedby Hooke'slaw and expressed by the formula: F=k*deltax, where k is the spring's constant, and delta xis the displacement of the spring. Transposing the terms such that we want to know the value of k,
k = F/deltax = 100N/(22 cm - 20cm)
k = 50 N/cm
Answer:
when the mass of an object is decreased, the acceleration will increase
when mass is increased, acceleration decreases
Answer:
C The launcher will fall off the platform and land D/2 to the left of the platform because the launcher is twice the mass of the ball.
Explanation:
The figure is missing: you can find it in attachment.
We can apply the law of conservation of momentum to check that the launcher will leave the platform with a speed which is half the speed of the ball. In fact, the total initial momentum is zero:

while the total final momentum is:

where
is the mass of the launcher
is the mass of the ball
is the velocity of the launcher
is the velocity of the ball
Since the total momentum must be conserved,
, so

Therefore we find

which means that the launcher leaves the platform with a velocity which is half that of the ball, and in the opposite direction (to the left).
Since the distance covered by both the ball and the launcher only depends on their horizontal velocity, this also means that the launcher will cover half the distance covered by the ball before reaching the ground: therefore, since the ball covers a distance of D, the launcher will cover a distance of D/2.
That depends on which angle you picked first, because that determines
which angles "the other two" are.
If you picked the right angle (90°) first, before you asked the question,
then the other two are acute angles, and they're also complementary