What will be the ratio between the initial and final kinetic energy of a car, if its velocity is tripled?

A certain atom has 26 protons, 26 electrons, and 30 neutrons. It mass number is?

pishuonlain [190]

The most common atom of iron has 26 protons and 30 neutrons in its nucleus. What are its atomic number, atomic mass, and number of electrons if it is electrically neutral? This atom has atomic number 26, atomic mass 56, and has 26 electrons.

4 0

3 years ago

Read 2 more answers

Jack and Jill have made up since the previous HW assignment, and are now playing on a 10 meter seesaw. Jill is sitting on one en

Airida [17]

Answer: 3 m.

Explanation:

Neglecting the mass of the seesaw, in order the seesaw to be balanced, the sum of the torques created by gravity acting on both children must be 0.

As we are asked to locate Jack at some distance from the fulcrum, we can take torques regarding the fulcrum, which is located at just in the middle of the length of the seesaw.

If we choose the counterclockwise direction as positive, we can write the torque equation as follows (assuming that Jill sits at the left end of the seesaw):

mJill* 5m -mJack* d = 0

60 kg*5 m -100 kg* d =0

Solving for d:

d = 3 m.

6 0

3 years ago

A proton is initially moving west at a speed of 1.10 106 m/s in a uniform magnetic field of magnitude 0.281 T directed verticall

kifflom [539]

Answer:

so here it will move in circle with radius 4.06 cm

Explanation:

As we know that proton is moving towards west while the magnetic field is vertically upwards

So here the force on the proton must be perpendicular to the velocity

So here we have

$F = q(\vec v \times \vec B)$

so here we have

$F = qvB sin90$

since force is perpendicular to the velocity so here it must be centripetal force

here we have

$\frac{mv^2}{R} = qvB$

so we have

$R = \frac{mv}{qB}$

$R = \frac{(1.66 \times 10^{-27})(1.10 \times 10^6)}{(1.6 \times 10^{-19})(0.281)}$

$R = 4.06 cm$

so here it will move in circle with radius 4.06 cm

8 0

3 years ago

A microwave oven operates on the principle that application of a high-frequency field causes electrically polarized molecules su

Tema [17]

Answer:

a

The time it would take the beef to reach a temperature of 0⁰C is t= 662 sec = 11.93 min

b)

The time it would take to heat the beef to uniform temperature of 80⁰C is

t = 365 sec =5.93 min

c

Efficient absorption of Microwave power is in regions of liquid water . Hence if the food or the microwave irradiation is not uniform, the power will be absorbed non-uniformly, resulting in a non-uniform temperature rise. Defrost region will absorb more energy per unit volume than frozen region.if food is of low thermal conductivity, there will be insufficient time for heat conduction to make the temperature more uniform.Use of low power allows more time for conduction to occur.

Explanation:

The explanation is shown on the first second and third uploaded image