1. They have evolved their leaves into spikes for minimum water loss through transpiration.
2. They have a waxy layer for minimum water loss.
3. They have thick walls for minimum water loss.
4. They can take water from atmosphere.
5. They change the photo energy from Sun into an intermediate stage and store it, so that they can make food even in night.
Answer:
1) The strength of the electromagnet increases → Place a magnetic core inside the coil of wire
2) The electromagnet turns off → Turn off the battery supply
3) The poles of the electromagnet reverse → Change the direction in which the current flows
Explanation:
when current passes through a coil it behaves a an electromagnet.
Magnetic field strength is given by
B = μ N I
N is no of turns and
I is the current through coil
μ is permeability of the medium or core in the coil.
1). Magnetic core increase permeability μ so it will strengthen magnetic field:
B = <u>μ</u> N I
2). When the battery turns off current becomes zeroi.e I=0
So B = μ N * 0
⇒ B = 0
so electromagnet turns off
3). Direction of magnetic field can be determine by right hand rule, i.e curl the fingers in the direction of current, thumb will point in the direction of north pole.
so changing current direction will change direction of magnetic field.
A: is potential
C: is losing kinetic energy and gaining potential energy
B: kinetic energy is at its highest
D: is loosing potential energy and gaining kinetic energy
Answer:
θ = 28.9
Explanation:
For this exercise let's use the law of refraction
n₁ sin θ₁ = n₂ sin θ₂
where we use index 1 for air and index 2 for water where the fish is
sin θ₂ = n₁ / n₂ sin θ₁
in this case the air repair index is 1 and the water 1.33
we substitute
sin θ₂ = 1 / 1.33 sin t 40
sin θ = 0.4833
θ = sin⁻¹ 0.4833
θ = 28.9
Answer:
10.93m/s with the assumption that the water in the lake is still (the water has a speed of zero)
Explanation:
The velocity of the fish relative to the water when it hits the water surface is equal to the resultant velocity between the fish and the water when it hits it.
The fish drops on the water surface vertically with a vertical velocity v. Nothing was said about the velocity of the water, hence we can safely assume that the velocity if the water in the lake is zero, meaning that it is still. Therefore the relative velocity becomes equal to the velocity v with which the fish strikes the water surface.
We use the first equation of motion for a free-falling body to obtain v as follows;
v = u + gt....................(1)
where g is acceleration due to gravity taken as 9.8m/s/s
It should also be noted that the horizontal and vertical components of the motion are independent of each other, hence we take u = 0 as the fish falls vertically.
To obtain t, we use the second equation of motion as stated;
Given; h = 6.10m.
since u = 0 for the vertical motion; equation (2) can be written as follows;
substituting;
Putting this value of t in equation (1) we obtain the following;
v = 0 + 9.8*1.12
v = 10.93m/s
