Explanation:
Given that,
The initial velocity of a skater is, u = 5 m/s
She slows to a velocity of 2 m/s over a distance of 20 m.
We can find the acceleration of skater. It is equal to the rate of change of velocity. So, it can be calculated using third equation of motion as follows :
a = acceleration
So, her acceleration is and she is deaccelerating. Also, her initial velocity is given i.e. 5 m/s.
Answer:
C
Explanation:
equation for pendulum period is
and it depends only on its length (and gravity which is not on the list of answers)
<u>Answer:</u> The kinetic energy of Natasha as she swim is 38.88 J
<u>Explanation:</u>
Force is defined as the mass multiplied by the acceleration of the object.
Mathematically,
where,
F = weight of Natasha = 530 N
m = mass of Natasha = ?
a = acceleration due to gravity =
Putting values in above equation, we get:
Speed is defined as the rate at which an object moves with respect to time. To calculate the speed, we use the equation:
where,
d = distance traveled = 72 m
t = time taken by Natasha = 1.0 min = 60 sec (Conversion factor: 1 min = 60 s)
Putting values in above equation, we get:
Kinetic energy is defined as the energy which is possessed due to its motion. It is also defined as the half of the product of mass of the object and square of the velocity of the object.
Mathematically,
where,
= kinetic energy of Natasha
m = mass of the Natasha = 54 kg
v = velocity of Natasha = 1.2 m/s
Putting values in above equation, we get:
Hence, the kinetic energy of Natasha as she swim is 38.88 J