If the graph represents speed, what is measured on the x and y axes? You need to specifically identify which axis is which.

A box of mass m = 1.80 kg is dropped from rest onto a massless, vertical spring with spring constant k = 2.00 ✕ 102 N/m that is

Rudik [331]

Answer:

spring compressed is 0.724 m

Explanation:

given data

mass = 1.80 kg

spring constant k = 2 × 10² N/m

initial height = 2.25 m

solution

we know from conservation of energy is

mg(h+x) = 0.5 × k × x² ...................1

here x is compression in spring

so put here value in equation 1 we get

1.8 × 9.8 × (2.25+x) = 0.5 × 2× 10² × x²

solve it we get

x = 0.724344

so spring compressed is 0.724 m

3 0

3 years ago

When light of wavelength 240 nm falls on a cobalt surface, electrons having a maximum kinetic energy of 0.17 eV are emitted. Fin

dusya [7]

Answer:

(a) 5.04 eV (B) 248.14 nm (c) $1.21\times 10^{15}Hz$

Explanation:

We have given Wavelength of the light \lambda = 240 nm

According to plank's rule ,energy of light

$E = h\nu = \frac{hc}{}\lambda$

$E = h\nu = \frac{6.67\times 10^{-34} J.s\times 3\times 10^{8}m/s}{ 240\times 10^{-9} m\times 1.6\times 10^{-19}J/eV}= 5.21 eV$

Maximum KE of emitted electron i= 0.17 eV

Part( A) Using Einstien's equation

$E = KE_{max}+\Phi _{0}$ , here $\Phi _0$ is work function.

$\Phi _{0}=E - KE_{max}$ = 5.21 eV-0.17 eV = 5.04 eV

Part( B) We have to find cutoff wavelength

$\Phi _{0} = \frac{hc}{\lambda_{cuttoff}}$

$\lambda_{cuttoff}= \frac{hc}{\Phi _{0} }$

$\lambda_{cuttoff}= \frac{6.67\times 10^{-34} J.s\times 3\times 10^{8}m/s}{5.04 eV\times 1.6\times 10^{-19}J/eV }=248.14 nm$

Part (C) In this part we have to find the cutoff frequency

$\nu = \frac{c}{\lambda_{cuttoff}}= \frac{3\times 10^{8}m/s}{248.14 \times 10^{-19} m }= 1.21\times 10^{15} Hz$

5 0

3 years ago

Is a 10 year old supposed to be doing algebra

forsale [732]

If he feels like, is interested in it, and is able to grasp it, then why not ? Why not indeed ?

3 0

3 years ago

Read 2 more answers

When an automobile moves with constant velocity, the power developed is used to overcome the frictional forces exerted by the ai

geniusboy [140]

Answer:

The total frictional force is 358.0 newtons

Explanation:

Power is the amount of average work (W) an object does on a period of time (Δt):

$P=\frac{W}{\Delta t}$

Remember average work is average force (F) times displacement (Δs):

$P=\frac{F \Delta s}{\Delta t}$

but displacement over time is average speed $v=\frac{\Delta s}{\Delta t}$ , then:

$P=Fv$ (1)

That is, the power of the car is the force the engine does times the speed of the car. As the question states, if the car is at constant velocity then the power developed is used to overcome the frictional forces exerted by the air and the road, that is by Newton's first law, the force the motor of the car does is equal the force of frictional forces. So, to find the frictional forces we only have to solve (1) for F:

$F=\frac{P}{v}$