Answer:
Explanation:
The package had the same velocity as the plane when it was dropped. Newton's 1st Law says that "an object in motion tends to stay in motion, at the same velocity, in a straight line unless acted on by an outside force".
There only outside force acting on the package was its weight -- that force is straight down. The horizontal velocity that the plane gave the package continued (as Newton said it would), so as it fell, horizontally it kept pace with the plane.
Answer: C
X = Displacement of the spring
Hooke's law: It states that the applied force F is proportional to the displacement of spring .
F ∝ x
Where, x = displacement of spring in meters
F = force, measured in Newtons
In another words The force F is equal to the constant K times the disparagement.
F = k.x
Where k is constant and it depends on elastic material.
Spring has restorative force.
If the spring moves in opposite direction then,
F = - k.x
A negative sign indicates that the spring resists and force is to the left. The compression of the spring is greater than the restoring force.
Example: A mass 'm' stretches a spring at a displacement x.
Answer: the external agent must do work equal to -1.3 × 10⁻⁸ J
Explanation:
Given that;
Mass M1 = 7.0 kg
r = 3.0/2 m = 1.5 m
Mass M2 = 21 kg
we know that G = 6.67 × 10⁻¹¹ N.m²/kg²
work done by an external agent W = -2GM2M1 / r
so we substitute
W = (-2 × 6.67 × 10⁻¹¹ × 21 × 7) / 1.5
W = -1.96098 × 10⁻⁸ / 1.5
W = -1.3 × 10⁻⁸ J
Therefore the external agent must do work equal to -1.3 × 10⁻⁸ J
The work done to pull the sister back on the swing is equal to the increase in potential energy of the sister:
(1)
where m is the sister's mass, g is the gravitational acceleration and
is the increase in altitude of the sister with respect to its initial position.
By calling
the angle of the chain with respect to the vertical, the increase in altitude is given by
(2)
where L is the length of the chain.
Putting (2) inside (1), we find
from which we can find the mass of the sister:
The object that goes through chemical change, changes completely to where you can not change it back to its original form. Physical change you can undo
