Our universe has an age to ~ 13.7 gyr and h. 67.74 km s-1 mpc-1. (a) show that the hubble time is 14.44 gyr and that to = 0.949h,. (b) show that the universe would be 1.42 times younger if it were always matter-dominated (c) show that the universe would be 1.9 times younger if it were always radiation-dominated (d) use the above to argue that radiation-dominated universes expand faster than matter-dominated ones (e) imagine our universe had a single component, show that, to get to = 13.7 gyr, w = -0.300. what kind of universe is this?

While the change in blank will remain the same during a collision, the force needed to bring an object to a stop can be blank if the time if collision is blank

An charge with mass m and charge q is emitted from the origin, (x, y)=(0,0). a large, flat screen is located at x=l. there is a target on the screen at y position y(h), where y(h) > 0. in this problem, you will examine two different ways that the charge might hit the target. ignore gravity in this problem. 1.assume that the charge is emitted with velocity v(0) in the positive x direction. between the origin and the screen, the charge travels through a constant electric field pointing in the positive y direction. what should the magnitude e of the electric field be if the charge is to hit the target on the screen? express your answer in terms of m, q, y(h), v(0), and l. 2.now assume that the charge is emitted with velocity v(0) in the positive y direction. between the origin and the screen, the charge travels through a constant electric field pointing in the positive x direction. what should the magnitude e of the electric field be if the charge is to hit the target on the screen? express your answer in terms of m, q, y(h), v(0), and l.

Asmall grinding wheel has a moment of inertia of 4.0×10−5 kg⋅m2 . what net torque must be applied to the wheel for its angular acceleration to be 150 rad/s2 ?