Question

checkp1.answer the following questions to check your understanding of the lesson.use the photo to answer questions 3 and 4.3. which statements are true about the house of cards on the table? choose all that applya. the force of gravity is acting on the cards and the table.b. the forces acting on the house of cards and the table are balanced.c. the forces acting on the house of cards and the table are unbalanced.d. the house of cards is not stable because too many unbalanced forces are acting on it.e. the house of cards is stable because balanced forces are acting on it and the forces are not changing.f. the house of cards is stable because there are no forces acting on any of the cards.2.4. suppose you pulled a card from the bottom layer. the house of cards would collapse, but why? choose terms to make the statement true.the elastic forces/gravitational forces would cause the cards to be more flexible/to be pulled down toward the table.use the photo to answer questions 5 and 6.5. the woman is using colorful letters to hold the drawing to the refrigerator. what type of force is pulling the letters toward the refrigerator?a. gravitational forceb. frictional forcec. air resistance forced. magnetic force6. the force acting between the refrigerator and magnets is a contact/a noncontact force. the forces acting on the sheet of paper are balanced/unbalanced because there is no change in the force / motion of the paper. the net force on the sheet of paper is zero / cant be calculated.

Explanation:

Question 3

Step1: Evaluate gravity statement

Gravity acts on all objects with mass, so A is true.

Step2: Evaluate force balance

The house of cards and table are stationary, so their forces are balanced (B true, C false).

Step3: Evaluate stability statements

Stable stationary objects have balanced forces, so E is true; D and F are false (unbalanced forces cause motion, and forces do act on the cards).

Question 4

Step1: Identify collapse force

When the bottom card is removed, gravity (the downward pull on mass) acts on the unsupported upper cards, pulling them down.

Question 5

Step1: Match force to scenario

Refrigerator magnets use magnetic force to stick to the metal fridge, so D is correct. Gravitational force pulls downward, friction opposes sliding, air resistance acts on moving objects, none match the horizontal pull of the letters to the fridge.

Question 6

Step1: Classify magnet force

Magnetic force acts without direct contact, so it is noncontact.

Step2: Evaluate paper force balance

The paper is stationary, so its forces are balanced.

Step3: Determine net force

Balanced forces result in a net force of zero, with no change in motion.

Answer:

Question 3:

A. The force of gravity is acting on the cards and the table.
B. The forces acting on the house of cards and the table are balanced.
E. The house of cards is stable because balanced forces are acting on it and the forces are not changing.

Question 4:

The gravitational forces would cause the cards to be pulled down toward the table.

Question 5:

D. magnetic force

Question 6:

The force acting between the refrigerator and magnets is a noncontact force. The forces acting on the sheet of paper are balanced because there is no change in the motion of the paper. The net force on the sheet of paper is zero.