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:
(c) 97 dB sound intensity level
Explanation:
We have given the intensity of the loud car horn 
We know that 
Now the sound intensity level is given by
, which is nearly equal to 97
So the sound intensity level will be 97 dB
So option (c) will be the correct option
Answer:
Option B. They use thermal updrafts to stay aloft
Explanation:
The sunlight warms the surface of the earth during noon and morning time and when this warming of the Earth's surface is not evenly done or uniform then this gives rise to the thermals. These are the rising air columns and rises when the air nearest to the earth heats up.
This is how some birds like vultures make use of the thermal updrafts to maintain flight.