Answer:
W = 12.96 J
Explanation:
The force acting in the direction of motion of the sand paper is the frictional force. So, we first calculate the frictional force:
F = μR
where,
F = Friction Force = ?
μ = 0.92
R = Normal Force = 2.6 N
Therefore,
F = (0.92)(2.6 N)
F = 2.4 N
Now, the displacement is given as:
d = (0.12 m)(45)
d = 5.4 m
So, the work done will be:
W = F d
W = (2.4 N)(5.4 m)
<u>W = 12.96 J</u>
No thats false. If your trying to say is true that people BELIEVED that then yes its true people believed it but if your talking about that question then its false
The angular momentum of the person is given by:

where

is the mass of the person,

is the tangential velocity, and

is the distance of the person from the center of rotation. Using these data, we find
Answer:
using the lens formula: 1/f = 1/u + 1/v
focal length f = -30 (negative because it is concave lens)
object distance u = 60
image distance v= unknown
1/-30 = 1/60 + 1/v
v = -20
So, the image is 20cm from lens (on the same side along with the object), and it is virtual (because of negative sign) and erect (concave lens must produce erect images).