Answer: W represents an element Y represents a mixture
Explanation: I just took a quiz on this and got it right. Good Luck
Answer:
P = 5880 J
Explanation:
Given that,
The mass of a person, m = 60 kg
The height of the stairs, h = 10 m
We need to find the gravitational potential energy of the person. The formula is as follows :

Substitute all the values,

So, the required gravitational potential energy is equal to 5880 J.
Answer: h = 3R
Explanation:
Using the law of conservation of energy,
Total energy at the beginning of the launch would be equal to total energy at any point.
kinetic energy + gravitational potential energy = constant
Initial energy of the projectile =
... (1)
where R is the radius of the Earth, M is the mass ofthe Earth, m is the mass of the projectile.
escape velocity, 
Total energy at height h above the Earth where speed of the projectile is half the escape velocity:
...(2)
(1)=(2)
⇒
⇒
⇒
⇒
⇒h = 3R
Thus, at height equal to thrice radius of Earth, the speed of the projectile would reduce to half of escape velocity.
Answer:
0.02
Explanation:
Force,
where N is normal reaction and coefficient of kinetic friction is
. Also, N is equivalent to mg ie N=mg where m is mass of an object and g is acceleration due to gravity. Making
the subject of the formula then

Substituting F with 2 N, m with 10 kg and g with 9.81 then
