Describe the difference between ‘conventional current’ and ‘electron flow’

You serve a volleyball with a mass of 2.1 kg. The ball leaves your hand with a speed of 30 m/s. The ball has—— energy. Calculate

Slav-nsk [51]

Answer:

945 j

Explanation:

You have just given the ball kinetic energy, which is given by the following equation:

KE= 1⁄2 m v2 = 1⁄2 (2.1 kg)(30 m/s)2 = 945 Joules

3 0

3 years ago

How do microwaves cook food or heat water?

Effectus [21]

Microwave ovens are so quick and efficient because they channel heat energy directly to the molecules (tiny particles) inside food. Microwaves heat food like the sun heats your face—by radiation. A microwave is much like the electromagnetic waves that zap through the air from TV and radio transmitters

7 0

3 years ago

When will you say a body is in a) uniform acceleration (b) non uniform acceleration

s2008m [1.1K]

Answer:

See below ~

Explanation:

Part (a) :

We can say a body is in uniform acceleration if the acceleration of the object remains constant with respect to time throughout its motion.

Part (b) :

We can say a body is non-uniform acceleration if the acceleration of the body varies with respect to time throughout its motion.

7 0

1 year ago

When two point charges are a distance d part, the electric force that each one feels from the other has magnitude F. In order to

Serjik [45]

Answer:

E) d/sqrt2

Explanation:

The initial electric force between the two charge is given by:

$F=k\frac{q_1 q_2}{d^2}$

where

k is the Coulomb's constant

q1, q2 are the two charges

d is the separation between the two charges

We can also rewrite it as

$d=\sqrt{k\frac{q_1 q_2}{F}}$

So if we want to make the force F twice as strong,

F' = 2F

the new distance between the charges would be

$d'=\sqrt{k\frac{q_1 q_2}{(2F)}}=\frac{1}{\sqrt{2}}\sqrt{k\frac{q_1 q_2}{(2F)}}=\frac{d}{\sqrt{2}}$

so the correct option is E.

8 0

2 years ago

Estimated speed of the vehicle

SSSSS [86.1K]

Really, Gundy ? ! ?

The formula for the car's speed is given and discussed in the box. The formula is

v = √(2·g·μ·d)

Then they tell you that μ is 0.750 , and then they tell you that d = 52.9 m . Also, everybody knows that 'g' is gravity = 9.8 m/s² .

They also tell us that the mass of the car is 1,000 kg, and they tell us that it took 3.8 seconds to skid to a stop. But we already have all the numbers in the formula without knowing the car's mass or how long it took to stop. The police don't need to weigh the car, and nobody was there to measure how long the car took to stop. All they need is the length of the skid mark, which they can measure, and they'll know how fast the guy was going when he hit the brakes !

Now, can you take the numbers and plug them into the formula ? ! ?

v = √(2·g·μ·d)

v = √( 2 · 9.8 m/s² · 0.75 · 52.9 m)

v = √( 777.63 m²/s²)

v = 27.886 m/s

Rounded to 3 digits, that's 27.9 m/s .

That's about 62.4 mile/hour .

3 0

3 years ago