Copper is a reddish orange, soft metal with a bright metallic luster. It is an excellent conductor of heat and electricity. Copper surfaces when exposed to air gradually turns to a dull, brownish color.
The speed is changing its direction all the time. There
is an acceleration which changes the direction of the speed – that is called
centripetal acceleration. Only uniform linear motions are considered to have no
acceleration.
This is the general formula for acceleration
a = dv/dt
When calculating dv, you should keep in mind the change
in the velocity vector’s direction. You can easily see in a graph that with dt
tending to 0 (so the length of the arc covered is also tending to 0), the difference
between vectors Vf and V0 has a direction which is perpendicular to velocity
(the shorter the arc, the closest the angle is to 90 degrees).
There is a formula (which can be deducted from the
previous formula) which allows you to calculate the acceleration:
a = v^2/r
Let’s talk about the units:
v is in m/s
r is in m
so v^2/r
is in (m/s)^2/m = (m^2/s^2)/m = m/s^2
which is the same unit as dv/dt:
dv/dt = (m/s)/s= m/s^2
Answer:
Speed of gamma rays = 3 x 10⁸ m/s
Explanation:
Given:
Frequency of gamma ray = 3 x 10¹⁹ Hz
Wavelength of gamma rays = 1 x 10⁻¹¹ meter
Find:
Speed of gamma rays
Computation:
Velocity = Frequency x wavelength
Speed of gamma rays = Frequency of gamma ray x Wavelength of gamma rays
Speed of gamma rays = [3 x 10¹⁹][1 x 10⁻¹¹]
Speed of gamma rays = 3 x [10¹⁹⁻¹¹]
Speed of gamma rays = 3 x [10⁸]
Speed of gamma rays = 3 x 10⁸ m/s
The answer I believe is c
Explanation
During the day when temperatures are higher, the snow melts and water enters the cracks in the rock. When the temperature drops below 0°C the water in the crack freezes and expands by about 9 per cent. This makes the crack larger.
Answer:
not clear pic...but it's definitely not A)
