The green wavelengths are reflected, causing green to be the only color we see in certain parts of plants.
Best of luck, my man.
Answer:
D. the linear velocity of the point of contact (relative to the inclined surface) is zero
Explanation:
The force of friction emerges only when there is relative velocity between two objects . In case of perfect rolling , there is no sliding so relative velocity between the surface and the point of contact is zero . In other words the velocity of point of contact becomes zero , even though , the whole body is in linear motion . It happens due point of contact having two velocities which are equal and opposite . One of the velocity is in forward direction and the other velocity which is due to rotation is in backward direction . So net velocity of point of contact becomes zero . Due to absence of sliding , displacement due to friction becomes zero . Hence work done by friction becomes zero.
Answer:
Time zone is one important factor in difference in location and this in turn affects the result of the resolution and rotation of shadow produced from the sun or other illumination.
Therefore someone at a place might see a clear large shadow due to shinny sun reflection and another a small or dull Shadow at same time if the intensity of the sun or lighting source is going down.
Explanation:
The closer a body/object is to a lighting source the larger the shadow it produces, and the farther the body the smaller the shadow produced.
Answer:
Kinetic energy cannot be negative
potential energy is a reference dependent quantity and it can be positive as well as negative both
Since potential energy is defined only for conservative force so it can not be found for friction force
Explanation:
Kinetic energy of an object is given by the formula
here we know that
m = mass of object that can not be negative
v = speed of the object and since its square is given here so it can not be negative
so Kinetic energy is always positive
potential energy is given as the energy due to the virtue of the position of object
so it is
so potential energy is a reference dependent quantity and it can be positive as well as negative both
Since potential energy is defined only for conservative force so it can not be found for friction force
Answer:
V = 331.59m/s
Explanation:
First we need to calculate the time taken for the shell fire to hit the ground using the equation of motion.
S = ut + 1/2at²
Given height of the cliff S = 80m
initial velocity u = 0m/s²
a = g = 9.81m/s²
Substitute
80 = 0+1/2(9.81)t²
80 = 4.905t²
t² = 80/4.905
t² = 16.31
t = √16.31
t = 4.04s
Next is to get the vertical velocity
Vy = u + gt
Vy = 0+(9.81)(4.04)
Vy = 39.6324
Also calculate the horizontal velocity
Vx = 1330/4.04
Vx = 329.21m/s
Find the magnitude of the velocity to calculate speed of the shell as it hits the ground.
V² = Vx²+Vy²
V² = 329.21²+39.63²
V² = 329.21²+39.63²
V² = 108,379.2241+1,570.5369
V² = 109,949.761
V = √ 109,949.761
V = 331.59m/s
Hence the speed of the shell as it hits the ground is 331.59m/s
