A women does 80.0 joules of work when she slides a book 4.0 meters on the floor. How much force does she apply to the book

Which of the following is the best hypothesis

tekilochka [14]

Answer:

Melting and frezzing are physical changes

5 0

3 years ago

Power Rating of a Resistor. The power rating of a resistor is the maximum power the resistor can safely dissipate without too gr

IgorLugansk [536]

(a) 273.9 V

The power rating of the resistor is given by

$P=\frac{V^2}{R}$

where

P is the power rating

V is the potential difference across the resistor

R is the resistance

If the maximum power rating is $P=5.0 W$ , and the resistance of the resistor is $R=15 k\Omega = 15000 \Omega$ , then we can find the maximum potential difference across the resistor by re-arranging the previous equation for V:

$V=\sqrt{PR}=\sqrt{(5.0 W)(15000 \Omega)}=273.9 V$

(b) 1.6 W

In this case, we have:

$R=9.0 k\Omega = 9000 \Omega$ is the resistance of the resistor

$V=120 V$ is the potential difference across the resistor

So we can find the power rating by using the same formula of part (a):

$P=\frac{V^2}{R}=\frac{(120 V)^2}{9000 \Omega}=1.6 W$

(c) Maximum voltage: 14.1 V; Rate of heat: 2.00 W and 3.00 W

Here we have two resistors of

$R_1 = 100 \Omega\\R_2 = 150 \Omega$

and each resistor has a power rating of

P = 2.00 W

So the greatest potential difference allowed in the first resistor is

$V=\sqrt{PR_1}=\sqrt{(2.00 W)(100 \Omega)}=14.1 V$

While the greatest potential difference allowed in the second resistor is

$V=\sqrt{PR_2}=\sqrt{(2.00 W)(150 \Omega)}=17.3 V$

So the greatest potential difference allowed not to overheat either of the resistor is 14.1 V.

In this condition, the power dissipated on the first resistor is 2.00 W, while the power dissipated on the second resistor is

$P_2 = \frac{V^2}{R_2}=\frac{(14.1 V)^2}{150 \Omega}=1.33 W$

And this corresponds to the rate of heat generated in the first resistor (2.00 W) and in the second resistor (1.33 W).

4 0

3 years ago

What is the difference between electromagnet and electromagnetism?

trapecia [35]

An electromagnet is a made coil associated with a ferromagnetic core. ... When an electric current flows through the wire the solenoid generates a magnetic field similar to that of a bar magnet. An electromagnet is a solenoid wound around a central iron core.

Electromagnetism is a process through which a material is magnetized (temporarily or permanently) by Electric current. ... This is Electromagnetism.

8 0

4 years ago

Two spherical objects have masses of 200 kg and 500 kg. Their centers are separated by a distance of 25 m. Find the gravitationa

ElenaW [278]

Answer:

1.07 x 10⁻⁸N

Explanation:

Given parameters:

Mass 1 = 200kg

Mass 2 = 500kg

Distance of separation = 25m

Unknown:

Gravitational attraction between the two bodies = ?

Solution:

To solve this problem, we use the equation of the universal gravitation;

F = $\frac{G mass 1 x mass 2}{r^{2} }$

G is the universal gravitation constant = 6.67 x 10⁻¹¹Nm²kg⁻²

r is the distance

Now insert the parameters and solve;

F = $\frac{6.67 x 10^{-11} x 200 x 500 }{25^{2} }$ = 1.07 x 10⁻⁸N

8 0

3 years ago

To ensure the greatest nutritional benefits, dietary guidelines suggest which of the following?

oee [108]

The answer would be D. Eating nutrient-dense foods

3 0

4 years ago

Read 2 more answers