The board is 2.50m high.
Why?
We can calculate how high was the board applying the Law of Conservation of Mechanical Energy. This Law states that the mechanical energy (kinematic and potential) will be conserved during the motion.
It can be described with the following formula:
At the top of the boar, the kinetic energy is equal to 0.
At the water, the potential energy is equal to 0.
So,
Hence, we have that the board is 2.50m high.
Have a nice day!
Answer:
U2 = 47.38m/s = initial velocity of B before impact
Explanation:
An example of the diagram is shown in the attached file because of missing angle of direction in the question
Mass A, B are mass of cars
A = 1965
B =1245
U1 = initial velocity of A = 52km/hr
U2 = initial velocity of B
V = common final velocity of two cars
BU2 = (A + B)*V sin ¤ ...eq1 y plane
AU1 = (A + B) *V cos ¤ ....equ 2plane
From equ 2
V = AU1/(A + B)*cos ¤
Substitute V into equation 1
We have
U2 = (AU1/B)tan ¤ where ¤ = angle of direction which is taken to be 30°
Substitute all parameters to get
U2 = (1965/1245)*52 * tan 30°
U2 = 47.38m/s
