## How many places can you put the lens to form a well-focused image of the candle flame on the wall?

A 4.0-cm-tall candle flame is 2.0 m from a wall. You happen to have a lens with a focal length of 42cm. A) How many places can you put the lens to form a well-focused image of the candle flame on the wall? Answer: 2 B) What are the distance between the candle and the

## How is this motion similar and different from that of a ball bouncing on a hard floor

How is simple harmonic motion similar AND different from that of a ball bouncing on a hard floor? (HINT: one similarity AND two differences) Answer Similarity -> Both ane oscillatory motion, both move to & fro. Differences Harmonic Mobius ane periodic and repeat after a fixed interval of time, But bouncing ball Amplitude. Continue Dechones,

## At what distance from the surface of the sphere is the electron’s speed half of its initial value?

A 2.6 mm -diameter sphere is charged to -4.6 nC . An electron fired directly at the sphere from far away comes to within 0.37 mm of the surface of the target before being reflected. What was the electron’s initial speed? At what distance from the surface of the sphere is the electron’s speed half

## What is the diameter of the radar beam at a distance of 30.0 km?

A radar for tracking aircraft broadcasts at 12 GHz microwave beam from a 2.0-m-diameter circular radar antenna. From a wave perspective the antenna is a circular aperture through which the microwaves diffracts. A. what is the diameter of the radar beam at a distance of 30 km? B. if the antenna emits 100 kW of

## How much work must be done to pull the plates apart to where the distance between them is 2.0 mm?

A capacitor consists of two 7.0-cm-diameter circular plates separated by 1.0 mm. The plates are charged to 160 V , then the battery is removed. 1) How much energy is stored in the capacitor? 2) How much work must be done to pull the plates apart to where the distance between them is 2.0 mm?

## What is the magnetic field at the center of the loop in the figure? (Figure 1)

What is the magnetic field at the center of the loop in the figure? (Figure 1) Answer The field will be sum of the fields due to a current carrying wire and a circular loop, B=\frac{\mu_{0} I}{2 \pi a}+\frac{\mu_{0} I}{2 a}=\frac{4 \pi \times 10^{-7} \times 5}{2 \times 0.01}\left(\frac{1}{\pi}+1\right)=4.14 \times 10^{-4} T

## What is the time constant for the discharge of the capacitors in the figure (figure 1)?

What is the time constant for the discharge of the capacitors in the figure (Figure 1) ? Answer \begin{aligned} R_{e q}=\frac{R_{1} R_{2}}{R_{1}+R_{2}}=\frac{|x|}{1+1}=\frac{1}{2} k\Omega=0.5 \mathrm{k\Omega} \\ C=4 \mathrm{\mu f} \\ \end{aligned} \begin{aligned} \text { Time constant } \tau=R C=\operatorname{Ref} \times C \\ = & \left(0.5 \times 10^{3} \Omega\right) \times\left(4 \times 10^{-6} \mathrm{~F}\right) \\ = & (5

## What is the electric potential at the point indicated with the dot in (Figure 1)?

What is the electric potential at the point indicated with the dot in (Figure 1)? Answer We have: AB = 3.0cm = CD and AD = BC = 4cm and A D^{2}+D C^{2}=A C^{2} \quad 2 \Rightarrow \quad A C^{2}=3^{2}+4^{2}=25 \Rightarrow \quad A C=5 \mathrm{~cm} Now electric potential at point C => \begin{aligned} V_{c} &=\frac{K\left(2

## What is the magnitude of the net force on the first wire in (figure 1)?

What is the magnitude of the net force on the first wire in (Figure 1)? Express your answer in newtons. What is the magnitude of the net force on the second wire in (Figure 1)? Express your answer in newtons. What is the magnitude of the net force on the third wire in (Figure 1)?

## What is the electric potential at the point indicated with the dot in the figure?

What is the electric potential at the point indicated with the dot in the figure? Express your answer to two significant figures and include the appropriate units. 1.0 nC 3.0 cm 3.0 cm 3.0 cm -2.0 nC 2.0 nC Use the properties of equilateral triangle: r=\frac{a}{\sqrt{3}}\\ =\frac{3}{\sqrt{3}}\\ =\sqrt{3} \mathrm{~cm}\\ =\sqrt{3} \times 10^{-2} \mathrm{~m}\\ The potential

## What is the strength of the electric field 0.1 mm above the center of the top surface of the plate?

A thin, horizontal, 14-cm-diameter copper plate is charged to 4.5 nC . Assume that the electrons are uniformly distributed on the surface. A. What is the strength of the electric field 0.1 mm above the center of the top surface of the plate? B. What is the strength of the electric field at the plate’s

## What is the magnetic field strength at point 1 in the figure?

Part A: What is the magnetic field strength at point 1 in the figure?(B_1= ? T) Part B: What is the magnetic field direction at point 1 in the figure? (out of the page or into the page?) Part C: What is the magnetic field strength at point 2 in the figure?(B_2= ? T) Part

## What is the width of the central maximum on a screen 2.0 m behind the slit?

A 0.50-mm-wide slit is illuminated by light of wavelength 500 nm. What is the width of the central maximum on a screen 2.0 m behind the slit? Please answer in mm. 3 Answers The halfwidth is the position of the 1st diffraction minimum, solved as follows: Θ = arcsin(m*lambda/(d)) = 1.00000016666674E-3 rad, 5.72957890623833E-2 deg y

## How much work does gravity do on the book?

A 1.7kg book is lying on a 0.80m -high table. You pick it up and place it on a bookshelf 2.3m above the floor. A) During this process, how much work does gravity do on the book? B) During this process, how much work does your hand do on the book? Answer (A) The expression

## Solve numerically for the magnitude of the force Fm in Newtons.

A box with mass m = 2.5 kg rests on the top of a table. The coefficient of static friction between the box and the table is μs = 0.61 and the coefficient of kinetic friction is μk = 0.32. Part (a) Write an expression for Fm the minimum force required to produce movement of

## A person bending forward to lift a load “with his back” rather than “with his knees”

A person bending forward to lift a load "with his back" rather than "with his knees" can be injured by large forces exerted on the muscles and vertebrae. The spine pivots mainly at the fifth lumbar vertebra, with the principal supporting force provided by the erector spinalis muscle in the back. For a person bending

## The Eiffel Tower in Paris is 984 ft tall and is made mostly of steel.

Problem 14.07 The Eiffel Tower in Paris is 984 ft tall and is made mostly of steel. Part A If this is its height in winter when its temperature is -8.00 ∘C, how much additional vertical distance must you cover if you decide to climb it during a summer heat wave when its temperature is

## A 4.0 cm tall candle flame is 2.0 m from a wall.

) A 4.0 cm tall candle flame is 2.0 m from a wall. You happen to have a lens with a focal length of 32 cm. How many places can you put the lens to form a well-focused image of the candle flame on the wall? For each location, what are the height and orientation