The statement ‘Big bang theorists
believe that the universe is expanding and will eventually contract’ is false. The
answer is letter B. The big bang theory suggests that the origin of the
universe began with that exploded and expanded. It also states that the
universe began in a single form of high condensed reactive matter and exploded
forming the galaxies, planets, stars and other celestial bodies.
Answer:
The glass rod remains charged due to electrification by the silk
Answer:
2 in front of water and 1 in front of oxygen
Explanation:
Answer:
c. vf is greator than v2, but less than v1
Explanation:
The principle of conservation of linear momentum states that when two or more bodies act upon one another, their total momentum remains constant.
In a system of colliding bodies the total momentum of the system just before the collision is the same as the total momentum just after the collision.
Collisions in which the kinetic energy is conserved are called elastic collision.
Collisions in which the kinetic energy is not conserved are called inelastic collisions. If the two objects stick together after the collision and move with a common velocity, the collision is said to be perfectly inelastic.
<em>The above scenario is a perfectly inelastic collision. The initial velocity of particle 1 was greater than particle 2 before collision. After collision, its velocity will reduce to a final velocity vf as it transfers some of its kinetic energy to particle 2; whereas, the velocity of particle 2 will increase to a final velocity vf as it absorbs some of the kinetic energy of particle 1.</em>
Therefore,
a. vf = v2 is wrong because vf is greater than v2
b. vf is less than v2 is wrong because vf is greater than v2
c. vf is greater than v2, but less than v1 is correct.
d. vf = v1 is wrong because vf is less than v1
Answer:
(a) 30 m/sec
(b) -50 m/sec
Explanation:
We have given initial velocity of ball u = 50 m/sec
Acceleration due to gravity 
(a) Time t = 2 sec
Now according to first equation of v = u-gt
So v=50-10×2=30 m/sec
(b) Time t = 10 sec
Now according to first equation of motion
So final velocity v = u-gt = 50-10×10 =-50 m/sec
