Answer:
Explanation:
Given
When we drop an object from height , suppose h
it takes time T
using equation of motion

where




here
because it dropped from a certain height


When height is increases to three times of original height
i.e. 
then time period becomes


Answer:
Case A
Explanation:
given,
size of bacteria = 1 mm x 1 mm
velocity = 20 mm/s
size of the swimmer = 1.5 m x 1.5 m
velocity of swimmer = 3 m/s
Viscous force

for the bacteria


for the swimmer


from the above force calculation
In case B inertial force that represent mass is more than the inertial force in case of bacteria.
Viscous force is dominant in case of bacteria.
So, In Case A viscous force will be dominant.
Answer:
our acceleration is 0 because there is a constant speed..
a = final speed - initial speed / time
final speed = initial speed ( since speed is constant)
therefore acceleration is 0
Answer:
2156J
Explanation:
Given parameters:
Height of lift = 10m
Mass = 22kg
Unknown:
Work done by the machine = ?
Solution:
Work done is the force applied to move a body through a certain distance.
So;
Work done = Force x distance
Here;
Work done = mass x acceleration due to gravity x height
Work done = 22 x 9.8 x 10 = 2156J
Answer:
a) 141.6m
b) 8.4m/s
Explanation:
a) to find the total displacement you use the following formula for each trajectory. Next you sum the results:

hence, the total distance is 141.6m
b) the mean velocity of the total trajectory is given by:

hence, the mean velocity is 8.4 m/s