Answer:

Given:
Mass (m) = 3.0 kg
Uniform speed (v) = 20 m/s
Length of string (r) = 40 cm = 0.4 m
To Find:
Tension in the string (T)
Explanation:
Tension (T) is the string will be equal to centripetal force (
).

Substituting value of m, v & r in the equation:


Tension in the string (T) = 3 kN
<u>Answer:</u> The velocity of released alpha particle is 
<u>Explanation:</u>
According to law of conservation of momentum, momentum can neither be created nor be destroyed until and unless, an external force is applied.
For a system:

where,
= Initial mass and velocity
= Final mass and velocity
We are given:

Putting values in above equation, we get:

Hence, the velocity of released alpha particle is 
Answer:
Explanation:
Given
speed of Electron 
final speed of Electron 
distance traveled 
using equation of motion

where v=Final velocity
u=initial velocity
a=acceleration
s=displacement


acceleration is given by 
where q=charge of electron
m=mass of electron
E=electric Field strength

Answer:
Volume of balloon = 1000 cm^3
Explanation:
The head of a normal person can be assumed as a sphere with radius 10 cm.
Volume of sphere
, where r is the radius.
We have approximate radius = 10 cm.
Approximate volume of head 
In the given options the closest value to the approximate volume is 1000 cm^3.
So, volume of head = Volume of balloon = 1000 cm^3
Answer:
Part a)

Part b)

Since the distance of other building is 15 m so YES it can make it to other building
Part c)

direction of velocity is given as
![[tex]\theta = 26.35 degree](https://tex.z-dn.net/?f=%5Btex%5D%5Ctheta%20%3D%2026.35%20degree)
Explanation:
Part a)
acceleration due to gravity on this planet is 3/4 times the gravity on earth
So the acceleration due to gravity on this new planet is given as


now the vertical displacement covered by the canister is given as

now by kinematics we have



Part b)
Horizontal speed of the canister is given as

now the distance moved by it



Since the distance of other building is 15 m so YES it can make it to other building
Part c)
Final velocity in X direction will remains the same

final velocity in Y direction



now magnitude of velocity is given as



direction of velocity is given as


![[tex]\theta = 26.35 degree](https://tex.z-dn.net/?f=%5Btex%5D%5Ctheta%20%3D%2026.35%20degree)