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4 years ago

A student is standing in an elevator that is

1 answer:

4 0

The force that the student exerts on the floor of the elevator must be "(1) less than the weight of the student when at <span>rest" since the elevator is "beating" him downward.</span>

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Two wires with the same resistance have the same diameter but different lengths. If wire 1 has length L 1 and wire 2 has length

SVEN [57.7K]

Answer with Explanation:

We are given that

Length of wire 1= $L_1$

Length of wire 2= $L_2$

Resistivity of copper wire= $\rho_1=1.7\times 10^{-5}\Omega-m$

Resistivity of aluminum wire= $\rho_2=2.82\times 10^{-5}\Omega-m$

Wire 1=Copper wire

Wire 2=Aluminum wire

Diameter of both wires are same and resistance of both wires are also same.

We know that

Resistance = $\frac{\rho l}{A}$

When diameter of wires are same then their cross section area are also same .

$l=\frac{RA}{\rho}$

When resistance and area are same then the length of wire depend upon the resistivity of wire .

The length of wire is inversely proportional to resistivity.

When resistivity is greater then the length of wire will be short and when the resistivity is small then the length of wire will be large.

$\rho_1$

Therefore, $L_1>L_2$

Hence, the length of wire 1 (copper wire) is greater than the length of wire 2 (aluminum).

$\frac{L_1}{L_2}=\frac{\frac{RA}{1.7\times 10^{-5}}}{\frac{RA}{2.82\times 10^{-5}}}=1.66$

$L_1=1.66L_2$

7 0

3 years ago

A university is planning to send an optical telescope into orbit. stuents attending the university will be able to view which of

kodGreya [7K]

Where are the answers? If there's anything about a white light coming from space I would choose that one.

3 0

4 years ago

Read 2 more answers

In a mass spectrometer, a single-charged particle (charge e) has a speed of 1.0 × 10 6 m/s and enters a uniform magnetic field o

Nonamiya [84]

Answer:

The mass is $m =6.4*10^{-28} \ kg$

Explanation:

From the question we are told that

The speed of the charge is $v = 1.0 *10^{6} \ m/s$

The magnetic field is $B = 0.20 \ T$

The radius is $r = 0.02 \ m$

The value of the charge is $e = 1.60 *10^{-19} \ C$

The centripetal acting on the charge moving in the circular orbit is mathematically represented as

$F_c = \frac{mv^2}{r }$

Now this centripetal force is due to the force exerted on the charge by the magnetic field on the charge which is mathematically represented as

$F_m = qv B sin\theta$

At the maximum of this magnetic force $\theta = 90 ^o$

$F_m = e v B sin(90)$

$F_m = e v B$

Now given that it is this magnetic force that is causing the circular motion we have that

$F_c = F_m$

=> $\frac{mv^2}{r } = ev B$

=> $m = \frac{e * B * r }{v }$

substituting values

$m = \frac{ 1.60 *10^{-19} * 0.20 * 0.020 }{1.0*10^{6} }$

$m =6.4*10^{-28} \ kg$

8 0

4 years ago

Estimate the theoretical fracture strength of a brittle material if it is known that fracture occurs by the propagation of an el

julia-pushkina [17]

The solution as per the attached photo.

4 0

4 years ago

Which of the following is an example of potential energy? (2 points)

gizmo_the_mogwai [7]

Answer: The correct answer is (a).

Explanation:

The potential energy is due to the position of the object.

The kinetic energy is due to the motion of the object.

In the case of a basketball sitting on a shelf, the basketball posses the potential energy due to some height.

In the case of a dog running across a field, a dog has kinetic energy due to its motion.

In a case of a bowling ball rolling down a lane, there is kinetic energy due to the motion of the bowling ball.

In the case of a teenager riding their bike, there is kinetic energy due to the motion of the bike.

Therefore, the correct answer is (a).

6 0

3 years ago