Mechanics and Forces Quiz

The fundamental property of an object that measures its ability to resist or oppose a change in its motion (its inertia) is:

• Weight

• Acceleration

• Resultant force

• Terminal velocity

• Mass

The simplified form of Newton’s Second Law of motion, which states the relationship between resultant force (F), mass (m), and acceleration (a) is:

• W=mg

• E=mc^2

• F=ma

• F= 1/2 mv^2

• a= v−u/t

According to Newton's First Law of motion, an object will remain at rest or move with constant velocity (uniform motion) unless:

• Its mass decreases.

• It experiences a large frictional force.

• An external resultant force acts on it.

• Its weight changes due to a change in gravity.

• Its mass and weight are equal in magnitude.

If the resultant force acting on a body is zero (F=0), based on the equation F=ma, what can be concluded about the acceleration of the body?

• Acceleration is inversely proportional to mass.

• Acceleration is directly proportional to mass.

• Acceleration cannot be determined.

• Acceleration will be maximum.

• Acceleration is zero (a=0), so the object is stationary or traveling at a constant velocity.

Which statement is not true regarding a pair of forces that satisfies Newton's Third Law of motion?

• They have equal magnitude.

• They are opposite in direction.

• They act on different objects.

• They are forces of the same type.

• They must be balanced (in a state of equilibrium). (They are equal and opposite, but they act on different objects, not balancing forces on one object.)

A train is decelerating as it comes into a station with an acceleration of −3.0 m s ^−2. If the train’s mass is 10 000 kg, what force must be provided by the braking system?

• 30 000 N

• −3 000 N

• 3 000 N

• −30 000 N

• 20 000 N

Which of the following statements correctly distinguishes between mass and weight?

• Mass and weight have the same SI base unit.

• Weight is a measure of an object's inertia.

• The mass of an object does not vary from place to place.

• Weight is a constant, while mass depends on gravity.

• Weight is mass multiplied by acceleration only when the object is moving.

The weight (W) of a body is equal to the product of:

• Mass and velocity.

• Resultant force and acceleration.

• Mass and terminal velocity.

• Its mass and the acceleration of free fall (g).

• Frictional force and velocity.

A moon-buggy is easier to lift on the Moon than on the Earth because:

• The mass of the moon-buggy decreases on the Moon.

• Lunar gravity is zero.

• The moon-buggy reaches terminal velocity faster.

• Its weight is smaller because the acceleration of free fall (g) on the Moon is smaller.

• Its inertia is smaller.

In the SI system, mass is a base unit (kilogram, kg), but weight is a force (Newton, N). In terms of SI base units, the Newton (N) is equivalent to:

• kg s ^−1

• m s^−2

• N m s^−2

• kg m s^−2

• m s