Answer:
a)1.37 s
b)∞ ( Infinite)
Explanation:
Given that
L= 47 cm ( 1 m =100 cm)
L= 0.47 m
a)
On the earth :
Acceleration due to gravity = g
We know that time period of the simple pendulum given as

Here

Now by putting the values

T=1.37 s
b)
Free falling elevator :
When elevator is falling freely then
( This is case of weightless motion)
Therefore

T=∞ (Infinite)
Answer:
5.886 J
Explanation:
Given:
The mass of the book is,
kg
Height of lift is,
m
Acceleration due to gravity is,
m/s²
Now, gain in gravitational potential energy is a function of change in position and is given as:

Here,
is the change in gravitational potential energy.
Plug in 0.5 kg for
, 9.81 for
and 1.2 for
. Solve for 

Therefore, the gain in gravitational energy of the book is 5.886 J.
Answer:
Explanation:the time taken to stop is 7seconds
The distance traveled by the car as it breaks is 63m
Answer:
2 kg
Explanation:
Assuming the rod's mass is uniformly distributed, the center of mass is at half the length.
Sum of the moments at the balance point:
-(Mg)(L/3) + (mg)(L/2 − L/3) = 0
(Mg)(L/3) = (mg)(L/2 − L/3)
(Mg)(L/3) = (mg)(L/6)
2M = m
M = 1 kg, so m = 2 kg.
The mass of the rod is 2 kg.