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3 years ago

A car travels 20 km southwards and then travel another 20km westward what is the displacement from the rest position

1 answer:

7 0

$\text{Hello there!}\\\\\text{We're trying to find displacement}\\\\\text{We would use the Pythagorean theorem to find the displacement:}\\a^2+b^2=c^2\\\\\text{We know that the car goes 20 km south and 20 km west}\\\\\text{When you draw it out, it should look like a triangle, you would be finding}\\\text{the length of the hypotenuse}\\\\\text{Plug in 20 to} \,\,a^2\,\, \text{and}\,\, b^2}\\\\20^2+20^2=c^2\\\\\text{Solve:}\\\\20^2+20^2=c^2\\\\400+400=c^2\\\\800=c^2\\\\\sqrt800=\sqrt c\\$

$\large\boxed{28.28}\\\\\normalsize\text{The displacment would be 28.28}$

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What is a tool that can be used to measure the size of a force

Travka [436]

The answer to this question would be: a spring scale.

The spring scale that you use to determine your body weight is actually a device that measures your body gravitational force. The force itself influenced by your body weight, that is why it can determine your body weight.
More weight means more force, more force will shrink the spring more.

7 0

3 years ago

If an electron moves in a circle of radius 21 cm perpendicular to a B field of 0.4 T, what are the speed of the electron and the

kodGreya [7K]

Answer:

$v = 4.048 *10^6$ m/s

Angular frequency = $1.92 * 10^7$

Explanation:

As we know

$v = \frac{qBr}{m}$

q is the charge on the electron = $3.2 * 10^{-19}$ C

B is the magnetic field in Tesla = $0.4$ T

r is the radius of the circle = $0.21$ m

mass of the electrons = $6.64 * 10^{-27}$ Kg

Substituting the given values in above equation, we get -

$v = \frac{3.2 * 10^{-19}*0.4*0.21}{6.64 * 10^{-27}} \\v = 4.048 *10^6$ m/s

Angular frequency =

$\frac{4.048 * 10^6 }{0.21} \\1.92 * 10^7$

8 0

3 years ago

Santa doesn't want to push a 25.0 kg wooden box across a wooden floor with a uk of 0.20 at

scZoUnD [109]

Answer:

49 N

Explanation:

In order to move the box at constant speed, the acceleration of the box must be zero (a=0): this means, according to Newton's second law,

F = ma

that the net force acting on the box, F, must be zero as well.

Here there are two forces acting on the box in the horizontal direction while it is moving:

- The force of push applied by the guy, F

- The frictional force, $F_f$

For an object moving on a flat surface, the frictional force is given by

$F_f = \mu_k mg$

where

$\mu_k$ is the coefficient of friction

m is the mass of the box

g is the acceleration of gravity

So the equation of the forces becomes

$F-\mu_k mg = 0$

And substituting:

$\mu_k = 0.20\\m = 25.0 kg\\g = 9.8 m/s^2$

We find the force that must be applied by the guy:

$F=\mu_k mg = (0.20)(25.0)(9.8)=49 N$

6 0

3 years ago

A fireman of 80 kg slides down a pole.When he reaches the bottom, 4.2 m below his starting point, his speed is 2.2 m/s . By how

levacccp [35]

Answer:

3099 J

Explanation:

The increase in thermal energy corresponds to the mechanical energy lost in the process.

The mechanical energy is given by the sum of gravitational potential energy and kinetic energy of the fireman:

$E=K+U$

At the top of the pole, the fireman has no kinetic energy, so all his mechanical energy is just potential energy:

$E=U=mgh=(80 kg)(9.8 m/s^2)(4.2 m)=3293 J$

When the fireman reaches the bottom, he has no gravitational potential energy, so his mechanical energy is just given by his kinetic energy:

$E=K=\frac{1}{2}mv^2=\frac{1}{2}(80 kg)(2.2 m/s)^2=194 J$

So, the loss in mechanical energy was

$\Delta E=3293 J-194 J=3099 J$

and this corresponds to the increase in thermal energy.

7 0

3 years ago

Radio waves travel at 3.00 · 108 m/s. Calculate the wavelength of a radio wave of frequency 600 kHz. (6.00 · 105 Hz).

frutty [35]

Hmm, I got that the wavelength is 500 meters.

4 0

3 years ago

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