Answer:
a) solar activity -- sudden eruptions of large bubbles of plasma and magnetic energy
and
d) solar flare -- sudden release of magnetic energy
Explanation:
We can start by eliminating the options that are definitely wrong.
A coronal mass ejection is not a relatively cool spot on surface of the sun, in fact such a spot is a sunspot, while a coronal mass ejection occurs when the magnetic field of the sun emerges as a loop. Thus, both options B and E are incorrect, leaving only A, C, and D. Option C makes no sense, as the sun's gravitational field does not 'churn'. Thus, only options A and D are left. A closer look at A and D reveals they are correct; solar flares are in fact sudden releases of magnetic energy, as seen in this quote from UC Berkeley's website; "Solar flares are caused by sudden changes of strong magnetic fields in the Sun's corona.". And solar activity is a blanket term for the effects of eruptions of plasma and magnetic energy from the sun.
<span>Let's convert the speed to m/s:
speed = (55 mph) (1609.3 m / mile) (1 hour / 3600 seconds)
speed = 24.59 m/s
Let's convert the mass to kilograms:
mass = (2135 lb) (0.45359 kg / lb)
mass = 968.4 kg
We can find the kinetic energy KE:
KE = (1/2) m v^2
KE = (1/2) (968.4 kg) (24.59 m/s)^2
KE = 292780 joules
The kinetic energy of the automobile is 292780 joules.</span>
W = 1/2k*x^2.
k = spring constant = 2500 n/m.
x = distance = 4 cm = 0.04m (convert to same units).
W = 1/2(2500)(0.04)^2 = 2J.
