Answer:11686.5 joules
Explanation:
elastic constant(k)=53N/m
extension(e)=21m
Elastic potential energy=(k x e^2)/2
Elastic potential energy=(53 x (21)^2)/2
Elastic potential energy=(53x21x21)/2
Elastic potential energy=23373/2
Elastic potential energy=11686.5
Elastic potential energy is 11686.5 joules
Answer:

Explanation:
Givens



The frequency is defined by

Where
is the speed of the wave in the string and
is its wave length.
The wave length is defined as 
Now, to find the speed, we need the tension of the wire and its linear mass density

Where
and the tension is defined as 
Replacing this value, the speed is

Then, we replace the speed and the wave length in the first equation

Therefore, the frequency is 
Answer:
577g
Explanation:
Given parameters:
Temperature change = 5.9°C
Amount of heat lost = 427J
Unknown:
Mass of the block = ?
Solution:
The heat capacity of a body is the amount of heat required to change the temperature of that body by 1°C.
H = m c Ф
H is the heat capacity
m is the mass of the block
c is the specific heat capacity
Ф is the temperature change
Specific heat capacity of lead is 0.126J/g°C
m = H / m Ф
m =
= 577g
Mass of the lead block is 577g
Newton's third law of motion is naturally applied to collisions between two objects. In a collision between two objects, both objects experience forces that are equal in magnitude and opposite in direction.For such a collision<span>, the forces acting between the two objects are equal in magnitude and opposite in direction</span>