Which is true about forces? Check all correct answers.
2 answers:
Answer:
b. Force is directly proportional to acceleration and mass. Objects with bigger mass and higher acceleration can produce bigger forces.
c. Forces are vectors - they always have magnitude and direction.
g. Forces of equal magnitude but in opposite directions have a zero net force and so are in a balanced state- at rest or in motion.
Explanation:
a. Forces are scalar quantities - they do not need direction.
False - forces are vector quantities, thus have both a magnitude and direction
b. Force is directly proportional to acceleration and mass. Objects with bigger mass and higher acceleration can produce bigger forces.
True - From Newton's 2nd Law , we see that force is directly proportional with acceleration and mass.
c. Forces are vectors- they always have magnitude and direction.
True
d. Objects at rest do not have any force acting on them.
False - Counterexample: an object laying at rest on a table has both normal force and the force of gravity acting on it.
e. Gravity only acts on objects that are falling.
False - Gravity acts on any object within the general universe. For an object to experience zero gravity, it would have to be in a vacuum or an infinite distance away from all objects in space.
f. Forces always require the Agent and the Receiver to touch to take effect.
False - Counterexample: Gravity is a no-contact force
g. Forces of equal magnitude but in opposite directions have a zero net force and so are in a balanced state- at rest or in motion.
True - Forces of equal magnitude and opposite direction will cause an object to have zero net force in the respective direction, assuming there are no other forces acting on the object.
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Answer:
Thus induced emf is 0.0531 V
Solution:
As per the question:
Diameter of the loop,
Thus the radius of the loop, R = 0.048 m
Time in which the loop is removed, t = 0.15 s
Magnetic field, B = 1.10 T
Now,
The average induced emf, e is given by Lenz Law:
where
= magnetic flux =
where
A = cross sectional area
Also, we know that:
e = 0.0531 V
The sketch is shown in the figure, where I indicates the direction of the induced current.
Answer:
Explanation:
= magnitude of charge on each proton = 1.6 x 10⁻¹⁹ C
= mass of each proton = 1.67 x 10⁻²⁷ kg
r = distance between the two protons = 1 x 10⁻¹⁵ m
Electric force between the two protons is given as
N
Gravitational force between the two protons is given as
N
Ratio is given as