Electric potential is measured in an SI unit called the _______

If a car is traveling 60 mph, its tires may have an rpm of 840. How many revolutions do the car’s tires make in one second?

Varvara68 [4.7K]

Forget about the car's speed. You don't need it.

The tires spin 840 rpm. That's 840 <em>Revolutions per Minute</em> .

There are 60 seconds in 1 minute. So something that happens 840 times in 1 minute happens (840 / 60) times every second.

(840 rev per minute) / (60) = <em>14 revs per second</em> .

5 0

3 years ago

A battery is replaced with one of lower emf. State and explain how the resistance of the lamps would have to change in order to

kow [346]

The brightness of the lamp is proportional to the current flowing through the lamp: the larger the current, the brighter the lamp.

The current flowing through the lamp is given by Ohm's law:

$I=\frac{V}{R}$

where

V is the potential difference across the lamp, which is equal to the emf of the battery, and R is the resistance of the lamp.

The problem says that the battery is replaced with one with lower emf. Looking at the formula, this means that V decreases: if we want to keep the same brightness, we need to keep I constant, therefore we need to decrease R, the resistance of the lamp.

3 0

3 years ago

the net external force on the 24-kg mower is stated to be 51 N. If the force of friction opposing the motion is 24 N, what force

-Dominant- [34]

Answer:

PART A)

External force will be 75 N

PART B)

distance moved will be 1.125 m

Explanation:

PART A)

Given that net force on the mower is

$F_{net} = 51 N$

now we also know that friction force due to ground is given as

$F_f = 24 N$

now we have

$F_{net} = F_{ext} - F_f$

$51 = F_{ext} - 24$

$F_{ext} = 75 N$

so external force will be 75 N

PART B)

deceleration due to friction when external force is removed from it

$a = \frac{F_f}{m}$

$a = \frac{24}{24} = 1 m/s^2$

now we can find the distance by kinematics

$v_f^2 - v_i^2 = 2 a d$

$0 - 1.5^2 = 2(-1)d$

$d = 1.125 m$

so the distance moved will be 1.125 m

6 0

3 years ago

What is the speed of a transverse wave in a rope of length 3. 1 m and mass 86 g under a tension of 380 n?

Nitella [24]

117 m/sec is the speed of a transverse wave in a rope of length 3. 1 m and mass 86 g under a tension of 380 n.

The wave speed v is given by

v= √τ/μ

where τ is the tension in the rope and μ is the linear mass density of the rope.

The linear mass density is the mass per unit length of rope :

μ= m / L = (0.086 kg)/(3.1 m)=0.0277 kg/m.

v= $\sqrt{ \frac{380 N}{0.0277 kg/m}}$ = 117.125 m/sec (approx. 117 m/sec

In physics, a transverse wave is a wave whose oscillations are perpendicular to the direction of the wave's advance. This is in contrast to a longitudinal wave which travels in the direction of its oscillations. Water waves are an example of transverse wave.

Transverse waves commonly occur in elastic solids due to the shear stress generated; the oscillations in this case are the displacement of the solid particles away from their relaxed position, in directions perpendicular to the propagation of the wave. These displacements correspond to a local shear deformation of the material. Hence a transverse wave of this nature is called a shear wave. Since fluids cannot resist shear forces while at rest, propagation of transverse waves inside the bulk of fluids is not possible.

Learn more about Transverse waves here : brainly.com/question/13761336

#SPJ4

3 0

2 years ago

The source of the earth’s magnetic field is found in the _____.

telo118 [61]

The source of the earth's magnetic field is found in the ;LIQUID MAGNETIZED IRON IN THE CORE OF THE EARTH. The earth's magnetic field is believed to be generated very deep down in the earth's core as a result of molten iron which it contains.

5 0

3 years ago

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Electric potential is measured in an SI unit called the ________.