Mass and weight Knowledge-Based Practice

Questions

1. 1.

   Why is a net force still required to accelerate an object in an environment where its weight is effectively zero?

   • A) Because the object retains its mass, which provides inertia that resists changes in motion.
   • B) Because the object loses its mass in weightlessness, creating an opposing resistance.
   • C) Because weight transforms into an equivalent inertial drag force during acceleration.
   • D) Because a gravitational force must always be established before any acceleration can occur.
2. 2.

   In the absence of air resistance, why do two objects of different masses accelerate at the same rate when falling freely near Earth's surface?

   • A) The ratio of gravitational force to mass is constant for all objects at that location.
   • B) The gravitational force exerted by Earth is identical on all objects regardless of mass.
   • C) The gravitational force acting on falling objects becomes zero in the absence of air.
   • D) The inertia of an object decreases during free fall to match the gravitational force.
3. 3.

   Two objects composed of different materials have identical weights at the exact same location on Earth. Which statement must be true regarding these two objects?

   • A) They have different masses because their densities are unequal.
   • B) They have equal masses and require identical net forces to achieve the same acceleration.
   • C) They must occupy identical volumes regardless of their densities.
   • D) They will have different weights from each other if both are transferred to the surface of the Moon.
4. 4.

   A scientific instrument has a mass of 50 kg and weighs 250 N on the surface of a newly discovered planet. What is the gravitational field strength on the surface of this planet?

   • A) 0.20 N/kg
   • B) 5.0 N/kg
   • C) 200 N/kg
   • D) 12,500 N/kg
5. 5.

   An exploratory rover has a mass of 40 kg. If the local gravitational field strength on the surface of a celestial body is 1.6 N/kg, what is the rover's weight on this surface?

   • A) 64 N
   • B) 25 N
   • C) 40 N
   • D) 392 N
6. 6.

   Which measuring instrument determines the mass of an object by balancing it against known reference masses, yielding an accurate reading regardless of variations in the local nonzero gravitational field strength?

   • A) A calibrated spring dynamometer
   • B) An equal-arm beam balance
   • C) A digital strain-gauge scale
   • D) A mechanical compression scale
7. 7.

   Which statement correctly describes a fundamental difference between an object's mass and its weight?

   • A) Mass is a force that depends on the local gravitational field, whereas weight is an intrinsic scalar property that remains constant everywhere.
   • B) Mass is a measure of an object's inertia and is measured in kilograms, whereas weight is the gravitational force acting on the object and is measured in newtons.
   • C) Mass changes whenever an object moves to a different planet, whereas weight is determined solely by the object's volume.
   • D) Mass is measured using a calibrated spring scale, whereas weight is measured exclusively by counting the total number of atoms.
8. 8.

   An astronaut transports a rock sample with a mass of 12 kg from Earth to the Moon, where the gravitational field strength is approximately one-sixth of that on Earth. How do the mass and weight of the rock sample on the Moon compare to its mass and weight on Earth?

   • A) The mass remains 12 kg, but its weight decreases.
   • B) The mass decreases to 2 kg, but its weight remains unchanged.
   • C) Both the mass and the weight decrease by a factor of six.
   • D) Both the mass and the weight remain completely unchanged.

Answers and step-by-step solutions appear after you finish the test.