Newton's first law of motion says something like "An object remains
in constant, uniform motion until acted on by an external force".
Constant uniform motion means no change in speed or direction.
If an object changes from rest to motion, that's definitely a change
of speed. So it doesn't remain in the state of constant uniform
motion (none) that it had when it was at rest, and that tells us
that an external force must have acted on it.
Answer and Explanation:
a. An oxygen-filled balloon is not able to float in the air, because the oxygen inside the balloon is of the same density, that is, the same "weight" as the oxygen outside the balloon and present in the atmosphere. The balloon can only float if the gas inside it is less dense than atmospheric oxygen. Helium gas is less dense than atmospheric gas, so if a balloon is filled with helium gas, that balloon will be able to float because of the difference in density.
b. The ship is able to float in the water because its steel construction is hollow and full of air. This makes the average density of this ship less than the density of water, which makes the ship lighter than water and for this reason, this ship is able to float. In addition, the ship is partially immersed, allowing the weight of the ship on the water to counteract the buoyant force that the water promotes on the ship. Weight and buoyant are two opposing forces that keep the ship afloat.
In a collision, the second collision is when an unsecured driver strikes the inside of the vehicle. It is a collision that happens between an occupant of a vehicle and the vehicle he is riding during the impact. The first collision would be the collision of the vehicle and the other object.
Answer:
speed
Explanation:
Given: an incomplete sentence
To fill: the blank
Solution:
Speed is not a vector quantity but a scalar quantity as it has magnitude but no direction.
Speed = Distance ÷ Time
You can calculate an <u>average</u> speed if you know both the total distance and the total time of the trip.
Average speed = Total distance ÷ Total time
