Q: Which of the following equations correctly represents the work done by a constant force $$\vec{F}$$ acting over a displacement $$\vec{d}$$?

$$W = F \times d \times \cos \theta$$

Question 1

A car travels 120 km north in 2 hours, then 80 km east in 1 hour. What is the magnitude of the car's average velocity over the entire trip?

Accepted Answer

$$\displaystyle 72.1\ \mathrm{km/h}$$

Question 2

Which of the following is a derived SI unit?

Accepted Answer

$$\displaystyle \mathrm{newton}$$

Question 3

A force of $$10\ \mathrm{N}$$ acts on a $$2\ \mathrm{kg}$$ object initially at rest. What is the object's velocity after $$5\ \mathrm{s}$$?

Accepted Answer

$$\displaystyle 5\ \mathrm{m/s}$$

Question 4

Which of the following statements about elastic and inelastic collisions is correct?

Accepted Answer

In an elastic collision, both kinetic energy and momentum are conserved.

Question 5

A $$0.5\ \mathrm{kg}$$ ball moving at $$4\ \mathrm{m/s}$$ collides head-on with a stationary $$0.5\ \mathrm{kg}$$ ball in a perfectly elastic collision. What is the velocity of the first ball after the collision?

Accepted Answer

$$\displaystyle 0\ \mathrm{m/s}$$

Question 6

Which of the following equations correctly represents the work done by a constant force $$\vec{F}$$ acting over a displacement $$\vec{d}$$?

Accepted Answer

$$W = F 	imes d 	imes \cos 	heta$$

Question 7

A $$60\ \mathrm{W}$$ light bulb is left on for $$10$$ hours. How much energy does it consume in kilowatt-hours?

Accepted Answer

$$\displaystyle 0.6\ \mathrm{kWh}$$

Question 8

Which of the following is the correct dimensional formula for force?

Accepted Answer

$$\displaystyle [M^1$L^1T$$^{-2}$$]$$

Question 9

A vector $$\vec{A}$$ has components $$A_x = 3$$ and $$A_y = 4. $$What is the magnitude of $$\vec{A}$$?

Accepted Answer

$$\displaystyle 5$$

Question 10

A $$2\ \mathrm{kg}$$ object moving at $$3\ \mathrm{m/s}$$ collides inelastically with a $$1\ \mathrm{kg}$$ object at rest. What is their common velocity after the collision?

Accepted Answer

$$\displaystyle 2\ \mathrm{m/s}$$

Question 11

Which of the following best describes the principle of conservation of energy?

Accepted Answer

Energy cannot be created or destroyed, only transformed from one form to another.

Question 12

A $$10\ \Omega$$ resistor is connected to a $$20\ \mathrm{V}$$ battery. What is the current through the resistor?

Accepted Answer

$$\displaystyle 2\ \mathrm{A}$$

Question 13

Which of the following is NOT a scalar quantity?

Accepted Answer

Velocity

Question 14

A metal rod of length $$2\ \mathrm{m}$$ expands by $$0.002\ \mathrm{m}$$ when heated from $$20^\circ\mathrm{C} to$$ $$120^\circ\mathrm{C}. $$What is the coefficient of linear expansion?

Accepted Answer

$$\displaystyle 1 	imes 10$$^{-5}$$\ ^\circ\mathrm{C}^{-1}$$

Question 15

A $$5\ \mathrm{kg}$$ object is dropped from a height of $$10\ \mathrm{m}. $$Ignoring air resistance, what is its velocity just before hitting the ground? ($$g = 9.8\ \mathrm{m/s}^2)$$

Accepted Answer

$$\displaystyle 14\ \mathrm{m/s}$$

Question 16

Which of the following is the correct expression for the first law of thermodynamics?

Accepted Answer

$$\Delta U = Q - W$$

Question 17

A $$3\ \mathrm{kg}$$ object moves with velocity $$\vec{v} = (2\hat{i} + 3\hat{j})\ \mathrm{m/s}. $$What is its momentum vector?

Accepted Answer

$$\displaystyle (6\hat{i} + 9\hat{j})\ \mathrm{kg\ m/s}$$

Question 18

Which of the following best describes Ohm's Law?

Accepted Answer

$$V = IR$$

Question 19

A $$1\ \mathrm{kg}$$ block slides down a frictionless incline of height $$5\ \mathrm{m}. $$What is its speed at the bottom?

Accepted Answer

$$\displaystyle 10\ \mathrm{m/s}$$

Question 20

A $$0.2\ \mathrm{kg}$$ ice cube at $$0^\circ\mathrm{C}$$ absorbs $$67.2\ \mathrm{kJ} of $$heat. How much of the ice melts? (Latent heat of fusion of ice $$= 334\ \mathrm{kJ/kg})$$

Accepted Answer

$$\displaystyle 0.2\ \mathrm{kg}$$

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