Answer:
IDC
Explanation:
I DON'T UNDERSTAND........
Answer:
it can be 15 or 75
Explanation:
using this equation
f = focal length
so = object distance
si = image distance
since we do not now what lens used, I assume from the problem the lens are positive (convex) but I don't know the image position because lens have two side.
1. the positif lens with negative image distance (it means object and image are in the same side of lens)
1/25 = 1/so - 1/37.5
1/so = 1/25 + 1/37.5 = 1/15
so = 15 cm in front of the lens (same side with the image)
2. the positif lens with positive image distance (it means object and image are not in the same side of lens)
1/25 = 1/so + 1/37.5
1/so = 1/25 - 1/37.5 = 1/75
so = 75 cm in front of the lens (not in the same side with the image)
Answer:
see the attachment
Explanation:
take coordinate system correctly. use formulas of projectile motion
Answer:
Explanation:
A component of 150 N in vertical direction will reduce the magnitude of reaction force.
reaction force exerted by the floor
= mg - 150 sin 30
where m is mass of the crate .
the magnitude of the horizontal component of the 150-newton force
150 cos30
= 130 N
This force tries to pull the crate in forward direction with acceleration but it has no acceleration . It is so because frictional force of equal magnitude acts on it in opposite direction which makes the net force acting on it equal to zero.
Hence frictional force is equal to 150 cos 30.
= 130 N .