C is correct. Only a closed circuit can carry current, opening a switch disconnects the circuit and stops current from flowing. Remember, all current flows in loops, if you can't make a loop out of it, current can't flow, and opening a switch, assuming no other paths for current exist, will completely stop the current.
Answer:
Explanation:
To estimate the focal length of a convex lens follow the following steps.
1. take a convex lens.
2. Stand near a window which is just opposite to a wall.
3. Look at a tree which is far away from the window by the convex lens.
4. focus the image of the tree on the wall which is opposite to the window.
5. You wll observe that by changing the position of convex lens a sharp and inverted and small image is seen on the wall.
5. Now measure the distance between the lens and the wall.
7. This distance is the rough focal length of the convex lens.
False, it does create pollution form the smoke stacks and after the process is done they have barrels of toxic waste
Answer
given,
mass of car (m) = 1200 Kg
speed of cur, u = 25 m/s
mass of truck(M) = 9000 Kg
speed of truck, u' = 20 m/s
v = 18 m/s
a) using conservation of momentum
m u + M u' = m v + M v'
1200 x 25 + 9000 x 20 = 1200 x 18 + 9000 x v'
9000 v' = 188400
v' = 20.93 m/s
b) To calculate losses, we will find the kinetic energies before & after collision. Any difference would give us the losses (in energy form).
(K E)₁= (K E)₂+ Losses
losses = (K E)₂ - (K E)₁
=
=
=9038 J