Light travels about 180 million kilometers in 10 minutes. How far does it travel in 1 minute? How far does it travel in 1 second
1 answer:
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Answer:
0.4
Explanation:
F-Fr=ma where F is applied force, Fr is friction, m is mass and a is acceleration.
Since the mass is moving with a constant velocity, there's no acceleration hence
where N is the weight of object and \mu is coefficient of kinetic friction.
the subject
Substituting F for 8 N and N for 20 N
Therefore, coefficient of kinetic friction is 0.4
Explanation:
Young' modulus is the ratio of normal stress to the longitudinal strain. Mathematically, it is given by :
Normal stress is given by force per unit area. Longitudinal strain is the change in length per unit original length.
The mathematical definition of Young's modulus is given by :
..........(1)
Where
is the change in length
F is the force
A is the area of cross section
So, the Young's modulus refers to the change in length of the object. Hence, the correct option is (b) "length".
Answer:
19.5°
Explanation:
The energy of the mass must be conserved. The energy is given by:
1)
where m is the mass, v is the velocity and h is the hight of the mass.
Let the height at the lowest point of the be h=0, the energy of the mass will be:
2)
The energy when the mass comes to a stop will be:
3)
Setting equations 2 and 3 equal and solving for height h will give:
4)
The angle ∅ of the string with the vertical with the mass at the highest point will be given by:
5)
where l is the lenght of the string.
Combining equations 4 and 5 and solving for ∅:
6)