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Questions in physics

[Open]A physics book rests upon a level table. Describe the forces acting on the book.

[Open]Describe how the motions of gas particles are related to the pressure exerted by the gas.

[Open]A 15 kg block has a constant acceleration of [tex]2.2 \, \text{m/s}^2[/tex] down a 30-degree incline. What is the magnitude of the friction force on the block?

[Open]A projectile is launched from ground level to the top of a cliff, which is 195 m away and 155 m high. If the projectile lands on top of the cliff 7.6 seconds after it is fired, find the initial velocity of the projectile (magnitude and direction). Neglect air resistance.

[Open]The amount of heat needed to raise 2.0 kg of a substance by 80 K is 33 kJ. What is the specific heat of the substance?

[Open]A car with a mass of 1000 kg is traveling at a constant speed of [tex]10 \, \text{m/s}[/tex]. Neglecting any friction, how much force will the engine have to supply to maintain this speed?

[Open]A 2-kg book is pushed along a table with a force of 4 N. Find the frictional force on the book if the book's acceleration is 1.5 m/s\(^2\). Explain how to find the frictional force.

[Open]What happens when a ray of light hits a mirror? Please provide a detailed answer.

[Open]A student notices that an inflated balloon gets larger when it is warmed by a lamp. Which best describes the mass of the balloon with this change?

[Open]**In a laboratory demo, a 12 V car battery powers two 12 V, 24 W lamps in parallel.** The current is measured using an ammeter (of resistance 10 ohms) which is connected in series with each of the bulbs in turn. What will the ammeter read? Comment on your answer. **Possible Answers:** 1) **1.2 A** Explanation: Using Ohm's Law, [tex]I = \frac{V}{R}[/tex], so [tex]\frac{12 \, \text{V}}{10 \, \text{Ohms}} = 1.2 \, \text{A}[/tex] 2) **0.75 A** Explanation: - The current of the bulbs normally is [tex]I = \frac{P}{V}[/tex], so [tex]I = \frac{24 \, \text{W}}{12 \, \text{V}} = 2 \, \text{A}[/tex]. - Resistance of each bulb: [tex]R = \frac{V}{I}[/tex], so [tex]R = \frac{12 \, \text{V}}{2 \, \text{A}} = 6 \, \text{Ohms}[/tex]. - Total resistance with the ammeter: [tex]6 \, \text{Ohms} + 10 \, \text{Ohms} = 16 \, \text{Ohms}[/tex]. - Current: [tex]I = \frac{V}{R}[/tex], so [tex]\frac{12 \, \text{V}}{16 \, \text{Ohms}} = 0.75 \, \text{A}[/tex].