Answer:
What is the radius of the table tennis ball?
⇒ 2.1 cm
What is the radius of the golf ball?
2.0 cm
Explanation:
divide the radius and round it to the nearest 10th place..... but hope that help ;)
Answer:
v = 7.95 m/s
Explanation:
Given that,
Wavelength of a wave, 
Frequency of a wave, f = 15 Hz
We need to find the speed of the wave. The speed of a wave is given by :

So, the wave move with a speed of 7.95 m/s.
Answer : The time passed in years is 20.7 years.
Explanation :
Half-life = 28.1 years
First we have to calculate the rate constant, we use the formula :



Now we have to calculate the time passed.
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = 
t = time passed by the sample = ?
a = initial amount of the reactant = 1.00 g
a - x = amount left after decay process = 0.600 g
Now put all the given values in above equation, we get


Therefore, the time passed in years is 20.7 years.
Answer:
Civilization's planet is most likely to be doomed because within the next million years the red giant star will possibly supernova.
Explanation:
Civilization's planet is most likely to be doomed because within the next million years the red giant star will possibly supernova. The supernova is the bursting of the star that has reached its end life. This leads to release of massive amount of energy, which can be more than the heat and energy released by the sun.
Explanation:
Spring is stretched by force f to distance
"X"
now here by force balance we can say
f = kx
k = !
now here we will we say that energy stored in the spring will convert into kinetic energy
kx² = mv²
(x² = mv²
now solving above equation we will have
PART 2)
now for half of the extension again we can use energy conservation
ka²-k(x/2)² = 1 {mv²
¾fx=mv²
now the speed is given as
3 fr 4m V=