Aspherical star of one solar mass and r = 0.5 solar radii rotates once every 60 days. at the end of its nuclear burning it collapses to a radius of 70 km. if 1/4 of the mass is lost in the collapse, what is the final period of rotation of the star? (the radius of the sun is 696,000 km.) (a) 0.157 s (b) 0.0393 s (c) 0.0175 s (d) 0.00983 s (e) 0.00162 s

u=13

v=30

s/t=u+1\2at

=13+431/2

=13+265.5

=278.5

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s