Answer:
there are 25 kg objective travelling at 2m/s to the right.
Answer:
The average acceleration of the bearings is 
Explanation:
Given that,
Height = 1.94 m
Bounced height = 1.48 m
Time interval 
Velocity of the ball bearing just before hitting the steel plate
We need to calculate the velocity
Using conservation of energy

Put the value into the formula



Negative as it is directed downwards
After bounce back,
We need to calculate the velocity
Using conservation of energy

Put the value into the formula



We need to calculate the average acceleration of the bearings while they are in contact with the plate
Using formula of acceleration

Put the value into the formula



Hence,The average acceleration of the bearings is 
Answer:
t = 96.1 nm
Explanation:
For strong reflection through liquid layer we know that the path difference between two reflected light rays must be integral multiple of wavelength
now we know that the path difference of two reflected light from thin liquid layer is given as

here we know that

t = thickness of layer
N = 0 (for minimum thickness of layer)

now we have


Let volume of empty boat be = 100% = 1V
and mass of boat be M
In water 10%, 0.1V of the volume is submerged.
Mass, m of 1200kg increases the submerging from 10%, 0.1V to 70%, 0.7V
M leads to 0.1V boat submerging
boat submerging.
M + 1200kg leads to 0.7V boat submerging.
This is 60%, 0.6 V increase
By comparison
(M+1200kg) * 0.1V = 0.7V * M
0.1M + 120kg = 0.7M
120kg = 0.7M - 0.1M
120kg = 0.6M
M = (120/0.6)kg
M = 200kg.
The mass of the boat is 200kg.
If you are given distance and a period of time, you can calculate
the speed. The velocity of an object is the rate of change of its position with
respect to a frame of reference, and is a function of time. Velocity is
equivalent to a specification of its speed and direction of motion (e.g. 60
km/h to the north).