Answer:
A
Explanation:
Constant speed (without change in direction) is not accelerating. If you are slowing down, speeding up, or changing direction, you are accelerating
Answer:
d. perfectly elastic
Explanation:
According to the kinetic theory for collisions of gas molecules:
1.The loss of energy is negligible or we can say that it is zero.
2.Molecules of the gas move in a random manner.
3.The collision between molecules and with the wall of the container is perfectly elastic.That is why loss in the energy is zero.
Therefore the correct answer will be d.
d. perfectly elastic
An object is lifted from the surface of a spherical planet to an altitude equal to the radius of the planet.
As a result, the object's <em>mass remains the same</em>, and its <em>weight decreases</em> to 1/4 of whatever it is when the object is on the planet's surface.
<span>Answer:
Assuming that I understand the geometry correctly, the combine package-rocket will move off the cliff with only a horizontal velocity component. The package will then fall under gravity traversing the height of the cliff (h) in a time T given by
h = 0.5*g*T^2
However, the speed of the package-rocket system must be sufficient to cross the river in that time
v2 = L/T
Conservation of momentum says that
m1*v1 = (m1 + m2)*v2
where m1 is the mass of the rocket, v1 is the speed of the rocket, m2 is the mass of the package, and v2 is the speed of the package-rocket system.
Expressing v2 in terms of v1
v2 = m1*v1/(m1 + m2)
and then expressing the time in terms of v1
T = (m1 + m2)*L/(m1*v1)
substituting T in the first expression
h = 0.5*g*(m1 + m2)^2*L^2/(m1*v1)^2
solving for v1, the speed before impact is given by
v1 = sqrt(0.5*g/h)*(m1 + m2)*L/m1</span>