Air caught in the ball of foil makes the ball less dense than water
Answer:
d. It is equal to the component of the gravitational force acting down the ramp.
Explanation:
The stationary crate is inclined at an angle with the horizontal. The Recall, Frictional Force is any Force that opposes motion.
Because the Force of Friction that is opposing the motion of the crate along the inclination side.
Therefore this Frictional force is balanced or equal to the force that is driving the inclined force.
Hence Frictional Force is equal to the Gravitational Force that is acting in the ramp, that is why the crate is stationery.
Answer:
Toward the centre of the circular path
Explanation:
The can is moved in a circular path: this means that it is moving by circular motion (uniform circular motion if its tangential speed is constant).
In order to keep a circular motion, an object must have a force that pushes it towards the centre of the circular trajectory: this force is called centripetal force, and its magnitude is given by

where m is the mass of the object, v its tangential speed, r the radius of the trajectory. This force always points towards the centre of the circular path.
Answer:
Your answer is D It does not need to be repeatable.
the reason for this is because C is correct.
You need to be able to experiment on something multiple times so that you can gather further data to imbedded your evidence in facts.