What do we mean when we say that the Sun is in gravitational equilibrium?
A) The Sun always has the same amount of mass, creating the same gravitational force.
B) The Sun maintains a steady temperature.
C) The hydrogen gas in the Sun is balanced so that it never rises upward or falls downward.
D) There is a balance within the Sun between the outward push of pressure and the inward pull of gravity.
D
You might also like to view...
Impulse: During World War I, Germany used a "Big Bertha" cannon to hurl shells into Paris 30 miles away. This gun also had a very long barrel. What was the reason for using a long barrel in these guns?
A. to exert a larger force on the shells B. to reduce frictional losses C. to allow the force of the expanding gases from the gunpowder to act for a longer time D. to increase the force exerted on the bullet due to the expanding gases from the gunpowder E. to reduce the force exerted on the bullet due to the expanding gases from the gunpowder
A spring (k = 200 N/m) is suspended with its upper end supported from a ceiling. With the spring hanging in its equilibrium configuration, an object (mass = 2.0 kg) is attached to the lower end and released from rest. What is the speed of the object after it has fallen 4.0 cm?
a. 90 cm/s b. 79 cm/s c. 96 cm/s d. 83 cm/s e. 57 cm/s
A space station orbits the Earth with constant speed. What can be said about the space station's acceleration?
1.It is zero because the space station moves with constant speed. 2.It is greater than 9.8 m/s2 because the space station is moving so quickly. 3.It is less than 9.8 m/s2 because the space station is so high above the Earth’s surface. 4.It is equal to 9.8 m/s2.
A projectile is fired straight up at a speed of 10 m/s, neglecting air resistance, the total time to return to its starting position is
A) 1 s. B) 2 s. C) 10 s. D) 20 s. E) not enough information