Answer:

Explanation:
As per energy conservation we know that the electrostatic potential energy of the charge system is equal to the initial kinetic energy of the alpha particle
So here we can write it as

now we know that


z = 79
here kinetic energy of the incident alpha particle is given as

now we have

now we have

Answer:
4v/3
Explanation:
Assume elastic collision by the law of momentum conservation:

where v is the original speed of car 1, v1 is the final speed of car 1 and v2 is final speed of car 2. m1 and m2 are masses of car 1 and car 2, respectively
Substitute 

Divide both side by
, then multiply by 6 we have



So the final speed of the second car is 4/3 of the first car original speed
Answer:
I) You walk barefoot on the hot street and it burns your toes.
II) When you get into a car with hot black leather in the middle of the summer and your skin starts to get burned.
Explanation:
In conduction mode of heat transfer we know that the energy is transferred from one system to other system due to direct contact of two bodies
Here due to this direct contact the energy is transferred via a given solid or liquid medium
In this type of heat transfer medium particles will remain in its own position only the energy is transferred.
So here we can say the correct answer will be
I) You walk barefoot on the hot street and it burns your toes.
II) When you get into a car with hot black leather in the middle of the summer and your skin starts to get burned.
Gravitational force depends on inverse square law. That is, gravitational force is inversely proportional to square of distance between asteroids.
As distance between them decreases, gravitational force increases. Hence A is correct.
Answer:
2.5 m/s²
Explanation:
Given,
Initial speed ( u ) = 10 m/s
Final speed ( v ) = 20 m/s
Time ( t ) = 4 seconds
To find : Acceleration ( a ) = ?
Formula : -
a = ( v - u ) / t
a = ( 20 - 10 ) / 4
= 10 / 4
= 5 / 2
a = 2.5 m/s²
Therefore,
The acceleration of the scooter is 2.5 m/s²