Answer:
please give me brainlist and follow
Explanation:
The angle and wavelength at which the light enters a substance and the density of that substance determine how much the light is refracted. ... When light passes from a more dense to a less dense substance, (for example passing from water into air), the light is refracted (or bent) away from the normal.
Length of the copper rod = 2.5 meters
Speed at which sound travels through copper = 3560 meter per second
Let us assume the time taken
by sound to cover the given distance = x seconds
We already know that
Speed = Distance/ Time
Then
Time = Distance/ Speed
x = 2.5/3560 seconds
= 0.0007 seconds.
This can ve done by hitting one end of the rod and then receiving the sound at the other end and using the stop clock to measure the time taken.
Answer: 20.2 m/s
Explanation:
From the question above, we have the following data;
M1 = 800kg
M2 = 1200kg
V1 = 13m/s
V2 = 25m/s
U (common velocity) =?
M1V1 + M2V2 = (M1 + M2). U
(800*13) + (1200*25) = (800+1200) * U
10400 + 30000 = 2000u
40400 = 2000u
U = 40400 / 2000
U = 20.2 m/s
Answer:
24 N
Explanation:
= mass of the cube = 
Consider the three cubes together as one.
= mass of the three cubes together = 
= acceleration of the combination = 2 ms⁻²
= Force applied on the combination
Using Newton's second law

= Force by the left cube on the middle cube
Consider the forces acting on left cube, from the force diagram, we have

You may know linear momentum is given by
P= mass.velocity.
Initially car is moving with some velocity so you know initial momentum of the car. Finally it comes to rest i.e final momentum of the car is 0. According to Newton's second law : Force = change in momentum /time. Applying this you'll get answer as 642840N. Hope it helped you. Revert back to me if you have any questions. Please check out the calculation it might be wrong!