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2 years ago

An electric motor is running on 120 V. The current is measured to be 2 A. How many ohms of resistance is the motor

Physics

1 answer:

valentinak56 [21]2 years ago

6 0

Answer:

60 ohms

Explanation:

$v = ir \\ 120 = 2i \\ i = 120 \div 2 \\ i = 60ohms$

If it is helpful pls follow

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A snowball is thrown with an initial x velocity of 7.5 m/s and an initial y velocity of 8.4 m/s . Part A How much time is requir

elena55 [62]

In order to calculate the time taken by the snowball to reach the highest point in its journey, we need to consider the variables along the y-direction.

Let us list out what we know from the question so that we can decide on the equation to be used.

We know that Initial Y Velocity $V_{iy}$ = 8.4 m/s

Acceleration in the Y direction $a_{y}$ = -9.8 m/ $s^{2}$ , since the acceleration due to gravity points in the downward direction.

Final Y Velocity $V_{fy}$ = 0 because at the highest point in its path, an object comes to rest momentarily before falling down.

Time taken t = ?

From the list above, it is easy to see that the equation that best suits our purpose here is $V_{fy} = V_{iy} + a_{y}t$

Plugging in the numbers, we get 0 = 8.4 - (9.8)t

Solving for t, we get t = 0.857 s

Therefore, the snowball takes 0.86 seconds to reach its highest point.

8 0

3 years ago

A conductor of radius r, length and resistivity ρ has resistance r. what is the new resistance if it is stretched to 4 times its

max2010maxim [7]

The resistance of a conductor is given by
$R= \frac{\rho L}{A}$
where L is the length of the wire, $\rho$ the resistivity of the material and A the cross-sectional area.

We can see that if all the other quantities do not change, if the new length of the conductor is 4 times the original length: $L'=4 L$ , then the new resistance is also 4 times the original value:
$R'= \frac{\rho L'}{A}= \frac{\rho 4 L}{A}=4 \frac{\rho L}{A}=4 R$

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3 years ago

Which is the correct equation for calculating the kinetic energy of an object ?

Andru [333]

Hello,

The answer is option B KE=1/2mv^2.

Reason:

In order to calculate the kinetic energy of a object you need to use option B which is the correct formula to find the kinetic energy.

If you need anymore help feel free to ask me!

Hope this helps!

~Nonportrit

3 0

3 years ago

Read 2 more answers

Let's take two balls, each of radius 0.1 meters and charge them each to 3 microCoulombs. Then, let's put them on a flat surface

salantis [7]

Explanation:

First, we will calculate the electric potential energy of two charges at a distance R as follows.

R = 2r

= $2 \times 0.1 m$

= 0.2 m

where, R = separation between center's of both Q's. Hence, the potential energy will be calculated as follows.

U = $\frac{k \times Q \times Q}{R}$

= $\frac{8.98 \times 10^{9} \times (3 \times 10^{-6} C)^{2}}{0.1}$

= 0.081 J

As, both the charges are coming towards each other with the same energy so there will occur equal sharing of electric potential energy between these two charges.

Therefore, when these charges touch each other then they used to posses maximum kinetic energy, that is, $\frac{U}{2}$ .