Hi, what is it you need help with?
Answer:
The oldest stars in spiral galaxies are younger than the oldest stars in elliptical galaxies.
Explanation:
Spiral galaxies have a greater star formation than elliptical galaxies, since the latter contain less gas and dust. Therefore, the rate of creation of new stars is lower in elliptical galaxies. These galaxies are dominated by old stars, with a long evolution. While the spiral galaxies have stars with a faster evolution.
I am like 98% sure it is C
Answer:
Torque, 
Explanation:
It is given that,
Force acting on the particle, 
Position of the particle,
We need to find the torque on the particle about the origin. It is equal to the cross product of position and the force. Its formula is given by :
The cross product of vectors is given by :

or

So, the torque on the particle about the origin
. Hence, this is the required solution.
Answer:
A
Explanation:
Friction is a force that makes an object slow down. Not speed up, cause it to move, or occurs in a vacuum. Friction is often caused by the surface an object is moving on.