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
Microwave<span> ovens are so quick and efficient because they channel </span>heat<span> energy directly to the molecules (tiny particles) inside </span>food<span>. </span>Microwaves heat food<span> like the sun heats your face—by radiation. A </span>microwave<span> is much like the electromagnetic waves that zap through the air from TV and radio transmitters</span>
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.
Answer:
E) d/sqrt2
Explanation:
The initial electric force between the two charge is given by:

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

So if we want to make the force F twice as strong,
F' = 2F
the new distance between the charges would be

so the correct option is E.
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 <em>tell</em> you that μ is 0.750 , and then they <em>tell</em> 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 <em>have</em> all the numbers in the formula <em>without</em> 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 <em>27.9 m/s </em>.
That's about 62.4 mile/hour .