Answer:
This equation is based on twin paradox - a phenomena where one of the twin travels to space at a speed close to speed of light and the other remains on earth. the twin from the space on return discovers that the one on earth age faster.
Solution:
= 10 years
v = 0.8c
c = speed of light in vacuum
The problem can be solved by time dilation equation:
(1)
where,
t = time observed from a different inertial frame
Now, using eqn (1), we get:

t = 16.67 years
The age of the twin on spaceship according to the one on earth = 25+16.67 =41.66 years
The correct choice is
B. Double-replacement reactions
in this type of reaction , two ionic compounds react and swaps their cations or anions giving two new compounds in the product. hence the double replacement reactions does not deal with the nucleus. all other terms like strong nuclear forces, radioactivity and nuclear decay deal with the nucleus.
Answer:
you want to know newtons first law here.
Explanation:
An object that is at rest stays at rest or stays in motion.
B. +Q, + W are the correct sign
Answer:
The velocity of each ball after the collision are 2.19 m/s and 2.58 m/s.
Explanation:
Given that,
Mass of object = 5 kg
Speed = 3 m/s
Mass of stationary object = 3 kg
Moving object deflected = 30°
Stationary object deflected = 31°
We need to calculate the velocity of each ball after collision
Using conservation of momentum
Along x-axis

Put the value into the fomrula


....(I)
Along y -axis

Put the value into the formula

...(II)
From equation (I) and (II)


Put the value of v₁ in equation (I)



Hence, The velocity of each ball after the collision are 2.19 m/s and 2.58 m/s.