Answer:
When you hit a baseball with a bat, you are applying a force only in the time while the bat is in contact with the ball, after that, the horizontal speed of the ball is constant. (if you ignore the friction of the air)
This happens because of the second Newton's law:
Force is equal to mass times the acceleration or:
F = m*a
If we do not have a force, then we do not have acceleration.
This means that the change in position for a fixed amount of time is constant, so horizontal speed is constant.
Answer:
F = 145 N
Explanation:
Given that,
Force applied by Jeff is 85 N and the force applied by Chris is 60 N. Both forces are acting in the same direction to push a rock up a hill. It means that net force is equal to the sum of these two forces.
So,
Net force on the rock = 85 N + 60 N
= 145 N
Hence, the net force on the rock is 145 N.
Question 1: The block in the illustration is floating in water, which has a density of 1.0 g/cm^3. About 40% of the block is below water. Even though we can't see the illustration, we estimate the density of the block to be about 0.40 g/cm
³ .
Question 2: The upward force that makes things float is called buoyancy.
Question 3: According to Pascal's principle, pressure through a fluid is uniform.
Question 4: A wing achieves lift by forcing air to move faster over the top of the wing.
Question 5: Pressure is measured as force per unit area.
Question 6: If the amount of a gas in a sealed container increases, the pressure in the container also increases.
The buoyant force on the lead balloon was caused by the air molecules in the room and thus these air molecules will be hitting the surface of the balloon and those collisions will cause a force per unit area.
Answer: Option D
<u>Explanation:
</u>
The term buoyant force is exerted mostly by objects getting fully or partially immersed in a fluid. This is the upward thrusting force exerted by the fluid on the bottom of the object to prevent the complete immersion of the object.
In other words, the buoyant force helps to keep the object floating. In case of balloon in air, the air pressure acts as the fluid which will be hitting the surface of balloon.
So, these collisions will prevent the balloon to fall down and to remain floating in air with an upward push from the collision of air molecules with the surface of balloon. So, the buoyant force acts on the lead balloon by collision of air molecules with the surface of balloon and pushing it in upward direction.
Answer:
mass of the body is constant as it is property of body, but weight is product of acceleration due to gravity and mass, which may vary from place to place because acceleration due to gravity is different for different places.
