Kinetic energy = (1/2) (mass) (speed²).
A Physicist in the canoe, or on a raft floating downriver next to the canoe, will say that the canoe's kinetic energy is zero.
A Physicist on the riverbank, watching the canoe drift by at 1 m/s, will say that its kinetic energy is 9 Joules.
They're both correct.
Answer:
0.000234 seconds
Explanation:
Since the row is 0.15m, its radius of rotation must be 0.15 / 2 = 0.075 m
We can start by calculating the angular speed of the rod:
Since one revolution equals to 2π rad. The speed in revolution per second must be
26800 / 2π = 4265 revolution/s
The number of seconds per revolution, or period, is the inverse:
1/4265 = 0.000234 seconds
Answer:
Explanation:
According to Coulomb's law, the magnitude of the electric force between two point charges is directly proportional to the product of the magnitude of both charges and inversely proportional to the square of the distance that separates them:
Here k is the Coulomb constant. In this case, we have 
, 
and 
. Replacing the values:
The negative sign indicates that it is an attractive force. So, the magnitude of the electric force is:
Answer:
It is easier to hear a musician in the classroom than outdoors
Explanation:
It is easier to hear a musician in the classroom due to the improved acoustics provided by the walls of the classroom whereby along with the direct sound of the musician, which is the lead source of the sounds, there is an increased number of indirect sound reaching the ear in the classroom than outdoors and due to precedence effect, all the sound appear to come from the musician
In music played outside, along side the direct sound from the musician, the indirect sound that reach the ear is echoed from maybe by only the ground while the majority of the sound from the music wanders away with the wind and in other directions as well as being absorbed such that speakers will be required to improve the sound of the music outdoors.
