Answer:
v = 2.18m/s
Explanation:
In order to calculate the speed of Betty and her dog you take into account the law of momentum conservation. The total momentum before Betty catches her dog must be equal to the total momentum after.
Then you have:
(1)
M: mass Betty = 40kg
m: mass of the dog = 15kg
v1o: initial speed of Betty = 3.0m/s
v2o: initial speed of the dog = 0 m/s
v: speed of both Betty and her dog = ?
You solve the equation (1) for v:
The speed fo both Betty and her dog is 2.18m/s
Use the impulse-momentum theorem.
Substitute your known values:
Hope this helps!
Answer:
a). 1.28333 seconds
b). 186.66 seconds
Explanation:
a). Given :
Distance between the earth and the moon, d = m
Speed of the radio waves, c = m/s
Therefore the time required for the voice of Neil Armstrong to reach the earth via radio waves is given by :
= 1.28333 seconds
b). Distance between Mars and the earth, d = m
Speed of the radio waves, c = m/s
So, the time required for his voice to reach earth is :
= 186.66 seconds
The answer is archimedes principle
Length of the sheet is given as
width of the sheet is given as
now let say its thickness is "t"
so the volume of the sheet is given as
mass of the sheet is given as
now we have
by solving above we have
so the thickness of sheet will be above