B) not work ,because the water would freeze
Answer:
7.5 km/h (2.1 m/s) due east
Explanation:
The average velocity of the person is given by:
where
d is the displacement
t is the time taken
In this problem,
d = 15 km is the displacement
t = 2.0 h is the time elapsed
so the average velocity is
and the direction is the same as the displacement (east).
We can also convert the velocity into SI units (m/s). We have:
d = 15 km = 15,000 m
t = 2.0 h * 3600 s/h = 7200 s
Answer:
Explanation:
Given that
Wavelength λ=192 nm
So energy of photon,E
Now by putting the values
We know that
Kinetic energy given as
-- During the time the ball is flying from the high roof to the low roof,
it's going to fall (100-25) = 75 meters.
How long does it take an object dropped from rest to fall 75 meters ?
Distance = (1/2) · (gravity) · (time)²
75 m = (4.9 m/s²) · (time)²
Time² = (75 m) / (4.9 m/s²)
Time² = 15.31 sec²
Time = √(15.31 sec²) = 3.91 seconds
So the ball has to cover the horizontal distance of 20 meters
in 3.91 seconds.
Distance = (speed) · (time)
20 m = (speed) · (3.91 sec)
Speed = (20 m) / (3.91 sec)
Speed = 5.11 m/s