Q: Which of the following best describes the dot product of two vectors $$\vec{A}$$ and $$\vec{B}$$?

$$\vec{A} \cdot \vec{B} = |\vec{A}| |\vec{B}| \cos \theta$$

Q: A $$2\,\mathrm{kg}$$ block is dropped from a height of $$5\,\mathrm{m}. $$What is its velocity just before hitting the ground? (Neglect air resistance, $$g = 9.8\,\mathrm{m/s^2$})$$

$$v = \sqrt{2 \times 9.8 \times 5}$$

Q: A $$0.05\,\mathrm{kg}$$ golf ball is hit with a velocity of $$40\,\mathrm{m/s}. $$What is its kinetic energy?

$$KE = \frac{1}{2} \times 0.05 \times 40^2$

Question 1

A block of mass $$m is $$pulled across a horizontal surface by a force $$F at an $$angle $$	heta$$ above the horizontal. If the block moves a distance $$d$$, what is the work done by the force $$F$$?

Accepted Answer

$$W = F d \cos 	heta$$

Question 2

Which of the following best describes the dot product of two vectors $$\vec{A}$$ and $$\vec{B}$$?

Accepted Answer

$$\vec{A} \cdot \vec{B} = |\vec{A}| |\vec{B}| \cos 	heta$$

Question 3

A spring with spring constant $$k is $$compressed by a distance $$x. $$What is the work done by the spring as it returns to its equilibrium position?

Accepted Answer

$$W = \frac{1}{2} k x^2$

Question 4

The area under a force vs. displacement graph represents:

Accepted Answer

The work done by the force

Question 5

A $$2\,\mathrm{kg}$$ block is dropped from a height of $$5\,\mathrm{m}. $$What is its velocity just before hitting the ground? (Neglect air resistance, $$g = 9.8\,\mathrm{m/s^2$})$$

Accepted Answer

$$v = \sqrt{2 	imes 9.8 	imes 5}$$

Question 6

Which of the following is the correct expression for instantaneous power delivered by a force $$\vec{F}$$ acting on a particle with velocity $$\vec{v}$$?

Accepted Answer

$$P = \vec{F} \cdot \vec{v}$$

Question 7

A conservative force is defined as a force for which:

Accepted Answer

The work done is independent of the path and depends only on initial and final positions

Question 8

The gravitational potential energy of a mass $$m at $$height $$h$$ above the ground is given by:

Accepted Answer

$$U = m g h$$

Question 9

A $$0.05\,\mathrm{kg}$$ golf ball is hit with a velocity of $$40\,\mathrm{m/s}. $$What is its kinetic energy?

Accepted Answer

$$KE = \frac{1}{2} 	imes 0.05 	imes 40^2$

Question 10

Which of the following statements about elastic collisions is correct?

Accepted Answer

Both momentum and kinetic energy are conserved

Question 11

In a perfectly inelastic collision between two objects, which of the following is true?

Accepted Answer

The objects stick together after the collision

Question 12

The impulse delivered to an object is equal to:

Accepted Answer

$$\Delta p = F \Delta t$$

Question 13

A $$100\,\mathrm{g}$$ ball is dropped from a height of $$25\,\mathrm{m}$$ and rebounds to a height of $$5\,\mathrm{m}$$ after hitting the ground. What is the change in the ball's mechanical energy?

Accepted Answer

$$\Delta E = m g (25 - 5)$$

Question 14

Which of the following is the correct expression for the potential energy stored in a spring compressed by $$x$$?

Accepted Answer

$$U = \frac{1}{2} k x^2$

Question 15

A $$1\,\mathrm{kg}$$ block slides down a frictionless incline of height $$h = 2\,\mathrm{m}. $$What is its speed at the bottom?

Accepted Answer

$$v = \sqrt{2 g h}$$

Question 16

The work-energy theorem states that:

Accepted Answer

The net work done on an object is equal to its change in kinetic energy

Question 17

A $$1500\,\mathrm{kg}$$ car crashes into a wall and comes to rest from $$20\,\mathrm{m/s}. $$What is the magnitude of the change in momentum?

Accepted Answer

$$\Delta p = 1500 	imes 20$$

Question 18

Which of the following is true for the conservation of linear momentum in a closed system?

Accepted Answer

The total linear momentum before and after an event is the same

Question 19

In a two-dimensional collision, which quantity is always conserved?

Accepted Answer

The vector sum of the momenta of all objects

Work, Energy, Power, and Momentum: Structured Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards