Answer:
I) You walk barefoot on the hot street and it burns your toes.
II) When you get into a car with hot black leather in the middle of the summer and your skin starts to get burned.
Explanation:
In conduction mode of heat transfer we know that the energy is transferred from one system to other system due to direct contact of two bodies
Here due to this direct contact the energy is transferred via a given solid or liquid medium
In this type of heat transfer medium particles will remain in its own position only the energy is transferred.
So here we can say the correct answer will be
I) You walk barefoot on the hot street and it burns your toes.
II) When you get into a car with hot black leather in the middle of the summer and your skin starts to get burned.
Answer:
C. 0.2 Hertz
Explanation:
The frequency of a spring is equal to the reciprocal of the period:
where
f is the frequency
T is the period
For the spring in this problem,
T = 5 s
therefore, the frequency is
Answer:
Option (c) is correct.
Explanation:
The apparent change in the frequency of light due to the relative motion between the source and the observer is called Doppler's effect.
When the source is moving towards the observer which is at rest, the apparent frequency increases and if the observer is moving away the frequency of sound decreases.
It occurs for both light and sound.
So, to explain the blue shift of light in the universe is due to the Doppler's effect of light.
Answer: 
Explanation:
The <u>centripetal acceleration</u> 
of an object moving in a uniform circular path is given by the following equation:
(1)
Where:
is the tangential velocity
is the radius of the circle
On the other hand, the tangential velocity is expressed as:
(2)
Where 
is the angular velocity, which can be found knowing the child makes 5 revolutions in 13.4s:
(3)
Substituting (3) in (2):
(4)
(5)
Substituting (5) in (1):
(6)
Finally:
