Answer:
7. Net constant force down the ramp
Explanation:
After the car is released and starts moving up the ramp, the only force that is applied on the car is weight because of the gravity, we were told that the friction force is neglected. the force because of the weight is given by:
where θ is the angle of the ramp.
as you can see those values won't change, so the force remains constant down the ramp.
A) To obtain an inverted image of an object of same size a convex lens is used.
B)
In this question we have given
Distance between candle flame and screen=4
it means distance between candle flame and lens +distance between lens and screen =4m
u+v= 4m
u= v
therefore, 2u= 4m
or, u=-2m ( u is taken negative because it lies on left side of the lens)
and v=2m
we have to find the focal length of convex lens
Hence, Focal length of the lens is 1m
and lens should be placed at a distance of 2m from the flame