Question 1

A 6.00-kg block is in contact with a 4.00-kg block on a horizontal frictionless surface as shown. A horizontal force of 20.0 N is applied to the 6.00-kg block. What is the magnitude of the force that the 6.00-kg block exerts on the 4.00-kg block?

Accepted Answer

$$8.00\ \mathrm{N}$$

Question 2

Three objects are connected as shown (2.0 kg on table, 1.0 kg and 3.0 kg hanging). The strings and pulleys are massless and frictionless. The coefficient of kinetic friction between the 2.0-kg block and the table is $$\mu_k = 0.25. $$What is the acceleration of the 2.0-kg block?

Accepted Answer

$$1.7\ \mathrm{m/s^2$}$$

Question 3

Block A (3.00 kg) rests on a rough plane inclined at $$30.0^\circ to $$the horizontal. The coefficient of static friction is $$\mu_s = 0.400. $$What minimum mass should block B have to just start block A sliding up the plane when connected as shown?

Accepted Answer

$$2.8\ \mathrm{kg}$$

Question 4

Two objects are connected by a massless string over a massless, frictionless pulley as shown. If $$M = 0.60\ \mathrm{kg}$$ and $$m = 0.40\ \mathrm{kg}$$, what is the magnitude of the acceleration of each object?

Accepted Answer

$$a = 1.96\ \mathrm{m/s^2$}$$

Question 5

A 100-kg block is released from rest from a height of 1.0 m and takes 0.90 s to reach the floor. The pulley is massless and frictionless. What is the mass $$m of $$the other block?

Accepted Answer

$$54\ \mathrm{kg}$$

Question 6

Which of the following statements best describes Newton’s third law?

Accepted Answer

For every action, there is an equal but opposite reaction acting on different objects.

Question 7

A mosquito runs head-on into a truck. Which is true during the collision?

Accepted Answer

The mosquito exerts the same force on the truck as the truck exerts on the mosquito.

Question 8

In a tug-of-war, two students pull on opposite ends of a massless rope with 100 N each. What is the tension in the rope?

Accepted Answer

$$100\ \mathrm{N}$$

Question 9

If two blocks are connected by a massless string and pulled across a frictionless surface, with block A having a larger mass than block B, how do the two tension forces compare?

Accepted Answer

$$T_1$$ \u003e $$T_2$$

Question 10

A block is accelerated across a frictionless table by a falling mass $$m$$ using a massless string and a massless, frictionless pulley. What is the tension $$T in $$the string compared to $$mg$$?

Accepted Answer

$$T \u003c mg$$

Question 11

Which of the following is NOT a property of an action/reaction pair according to Newton’s third law?

Accepted Answer

They can cancel each other out on a single object.

Question 12

A car is propelled forward primarily due to which force?

Accepted Answer

Static friction

Question 13

If two objects are connected by a rope over a pulley and move together, what is the acceleration constraint?

Accepted Answer

$$a_{Ax} = -a_{By}$$

Question 14

When analyzing interacting objects, what is the first step in the problem-solving strategy?

Accepted Answer

Identify which objects form the system.

Question 15

A block of mass $$m is $$hanging from a rope attached to a ceiling. What is the tension in the rope if the block is at rest?

Accepted Answer

$$T = mg$$

Newton’s Third Law and Interacting Objects – Step-by-Step Physics Guidance

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