Answer: A
Explanation: isotopes of the same thing element have the same number of protons in the nucleus but differ in the number of neutrons.
The correct answer would be D. A new experiment would be needed to be done in order to test the conclusions. In science there is no authority, data is the only thing that matters. So if we have two different conclusions from the same date the only solution is to perform more tests and more experiments to see what is correct.
Answer:Expression given below
Explanation:
Given mass of spring
Compression in the spring
Let the spring constant be K
Using Energy conservation
potential energy stored in spring =Kinetic energy of Block


now conserving momentum


where
is the final velocity
Answer:
The value is 
Explanation:
From the question we are told that
The mass of each sphere is 
The length of the string is
The angle of with the vertical is 
The acceleration due to gravity is 
Generally the force acting between the forces is mathematically represented as

=> 
Generally from Pythagoras theorem the radius of the circular curve created by the force is

=> 
=>
=> 
=> 
=> 
consider the motion along the X-direction
X = horizontal displacement = 80 m
= initial velocity along the x-direction = v Cos60
t = time of travel
using the equation
X =
t
80 = (v Cos60) (t)
t = 160/v eq-1
consider the motion in vertical direction :
Y = vertical displacement = 20 m
= initial velocity in Y-direction = v Sin60
a = acceleration = - 9.8 m/s²
t = time of travel = 160/v
using the equation
Y =
t + (0.5) a t²
20 = (v Sin60) (160/v) + (0.5) (- 9.8) (160/v)²
v = 32.5 m/s