03.1 Weight

What is the unit of mass in the International System of Units (SI)?

• Gram

• Kilogram

• Pound

• Newton

Answer explanation

The unit of mass in the International System of Units (SI) is the kilogram. It is the base unit for mass, while the gram is a derived unit. The pound is a unit of weight, and the newton is a unit of force.

Tags

DOK Level 1: Recall

• 980 N

• 100 N

• 9.8 N

• 1000 N

Answer explanation

Weight is calculated using the formula: weight = mass × gravity. Here, weight = 100 kg × 9.8 m/s² = 980 N. Therefore, the correct answer is 980 N.

Tags

DOK Level 2: Skill/Concept

What is the mass of an object on the moon if its mass on Earth is 100 kg?

• 16.67 kg

• 100 kg

• 600 kg

• 0 kg

Answer explanation

The mass of an object remains constant regardless of its location. Therefore, an object with a mass of 100 kg on Earth also has a mass of 100 kg on the Moon.

Tags

DOK Level 1: Recall

Assuming the acceleration due to gravity on the moon is one-sixth of that on Earth, what is the weight of a 100 kg object on the moon?

• 16.33 N

• 98 N

• 163.33 N

• 980 N

Answer explanation

To find the weight on the moon, use the formula: weight = mass × gravity. On Earth, gravity is approximately 9.81 m/s², so on the moon it is 9.81/6 = 1.635 m/s². Thus, weight = 100 kg × 1.635 m/s² = 163.33 N.

Tags

DOK Level 2: Skill/Concept

Explain why the mass of an object remains the same on both Earth and the moon.

• Mass is dependent on gravity.

• Mass is the amount of matter in an object, which does not change with location.

• Mass changes with the object's speed.

• Mass is affected by temperature.

Answer explanation

Mass is the amount of matter in an object, and it remains constant regardless of location. This is why an object's mass is the same on both Earth and the moon, unlike weight, which varies due to differences in gravity.

Tags

DOK Level 2: Skill/Concept

A man can exert the same force with his legs on both Earth and the moon. Will he be able to jump higher on the moon? Why or why not?

• Yes, because the gravitational force is weaker on the moon.

• No, because his mass is greater on the moon.

• Yes, because his weight is greater on the moon.

• No, because the gravitational force is stronger on the moon.

Answer explanation

Yes, because the gravitational force is weaker on the moon. This allows the man to jump higher since he can exert the same force, but the lower gravity means less weight to overcome.

Tags

DOK Level 3: Strategic Thinking

• 490 N

• 50 N

• 9.8 N

• 500 N

Answer explanation

To calculate the force of gravity, use the formula F = m * g. Here, m = 50 kg and g = 9.8 m/s². Thus, F = 50 kg * 9.8 m/s² = 490 N. Therefore, the correct answer is 490 N.

Tags

DOK Level 2: Skill/Concept

If a 60 kg object weighs 360 N on a certain planet, what is the acceleration due to gravity on that planet?

• 6 m/s²

• 9.8 m/s²

• 3.6 m/s²

• 60 m/s²

Answer explanation

To find the acceleration due to gravity, use the formula: weight = mass × gravity. Here, 360 N = 60 kg × gravity. Solving for gravity gives: gravity = 360 N / 60 kg = 6 m/s². Thus, the correct answer is 6 m/s².

Tags

DOK Level 3: Strategic Thinking

Discuss the relationship between mass and weight. How does this relationship change when moving from Earth to the moon?

• Mass and weight are the same on both Earth and the moon.

• Mass remains constant, but weight changes due to different gravitational forces.

• Both mass and weight change when moving from Earth to the moon.

• Mass changes, but weight remains constant.

Answer explanation

Mass is a measure of the amount of matter in an object and remains constant regardless of location. Weight, however, is the force exerted by gravity on that mass, which changes when moving from Earth to the moon due to different gravitational forces.

Tags

DOK Level 3: Strategic Thinking

What is the weight of a 75 kg object on the moon if the gravitational acceleration is 1.63 m/s²?

• 122.25 N

• 75 N

• 490 N

• 735 N