Answer:b
Explanation:
Given
Woman earn 50% more than her husband
Total sum of their money is
Suppose man earns
so women earns
Sum of their money is
Women earns
The component of weight(
mg) that is responsible for the motion of boxes on ramp is:
Where m = mass of the boxes.
g = Acceleration due to gravity = 9.8
= The angle the ramp makes with the ground. In this case it is 30°.
Since the frictional force is:
μ*N.
Where,
μ = Frictional Coefficient
N = Normal to the ramp =
Therefore, the frictional force becomes =
= μ*
Apply Newton's second law we would get:
- μ*
=
=>
=
μ
-- (A)
Now according to equation of motion:
Where x = 5.8m
= 0
= 0
= 10.24
Plug in the value in the above equation you would get:
= 1.1328
Plug in
in equation (A) and solve for
μ, you would get,
μ = 0.4439
The potential energy of the ball before it falls is (mass) (gravity) (height) =
(0.5 kg) (9.8 m/s²) (4 m) = 19.6 joules
The kinetic energy of the ball when it hits the ground is (1/2) (mass) (speed)² =
(1/2) (0.5 kg) (5 m/s)² = (0.25 kg) (25 m²/s²) = 6.25 joules
a). The <em>energy lost</em> to air resistance during the fall is (19.6J - 6.25J) = <em>13.35 Joules. </em><em>Energy is never destroyed, so these missing joules had to go somewhere. This is the </em><em>work done on the ball by air resistance</em><em> during the fall of the ball.</em>
b). Air resistance worked on the ball all during the fall of 4 meters.
Work = (force) x (distance)
13.35 Joules = (force) x (4 meters)
Divide each side by (4 meters) :
Average force = (13.35 Joules / 4 meters)
<em>Average force = 3.3375 Newtons</em>
Answer
Correct Answer is D( Marie Sklodowska-Curie)
Explanation
Marie Curie is known for her contributions such as the discovery of Radium and other key elements help us out every day, especially when getting an x-ray.
Marie Curie worked with her husband Pierre Curie and received the Nobel Prize in 1903 for their research of discovery of radium. Marie curie and Pierre Curie published a research paperin which they mentioned the processes they have used to isolate radium. Marie Curie works described the effects of radium on living organisms. Marie Curie showed it could damage tissue, and this discovery was used against cancer and other diseases.