Answer:
θr = 55.2 °
Explanation:
The law of reflection states that the angle of incidence and the angles of reflection is the same.
Let's use trigonometry to find the angle between the reflected ray, where the horizontal distance x = 55.9 cm and the vertical distance is y = 38.9 cm
tan θ = y / x
tan θ = 38.9 / 55.9
θ = tan⁻¹ (0.6959)
θ = 34.8°
This angle is measured with respect to the x-axis (horizontal), but in general the angles in optics are measured from the y-axis so that the angle is
θ = 90 - 34.8
θr = 55.2 °
Answer:
The air resistance on the skydiver is 68.6 N
Explanation:
When the skydiver is falling down, there are two forces acting on him:
- The force of gravity, of magnitude 
, in the downward direction (where m is the mass of the skydiver and g is the acceleration due to gravity)
- The air resistance, 
, in the upward direction
So the net force on the skydiver is:
where
m = 7.0 kg is the mass
According to Newton's second law of motion, the net force on a body is equal to the product between its mass and its acceleration (a):
In this problem, however, the skydiver is moving with constant velocity, so his acceleration is zero:
Therefore the net force is zero:
And so, we have:
And so we can find the magnitude of the air resistance, which is equal to the force of gravity:
Answer:
The correct option is D
Explanation:
From the question we are told that
The intensity of the first electromagnetic wave is 
The amplitude of the electric field is 
The intensity of the second electromagnetic wave is 
Generally the an electromagnetic wave intensity is mathematically represented as
Looking at this equation we see that
=> ![\frac{I_1}{I_2} = [ \frac{ E_{max}_1}{ E_{max}_2} ] ^2](https://tex.z-dn.net/?f=%5Cfrac%7BI_1%7D%7BI_2%7D%20%20%3D%20%20%5B%20%5Cfrac%7B%20E_%7Bmax%7D_1%7D%7B%20E_%7Bmax%7D_2%7D%20%5D%20%5E2)
=> 
=> 
=> 
Answer:
0.34s, 8.5m,31.89m
Explanation:
The above motion defines a projectile motion.
Now the athletes lands on a cliff 30° to the horizontal this means the velocity at that point would be 25m/s cos30°
Now from Newton's law of motion.
The body would be decelerating so,
V = u - gt
Where u is initial velocity and v is final velocity. g is acceleration of free fall due to gravity.
Hence,
V-U/ -g = t
Hence 25cos30 - 25/ -9.8 = 0.34s.
2.Now the length of the jump is defined as the total horizontal distance which is marked off by the horizontal velocity and time taken for take off and landing.
Hence Distance,S = u × t
25 ×0.34 =8.5m.
3. The maximum height is defined that at that point the Final velocity is 0m/s
Now the initial velocity is 25m/s
From Newton's law that;
V2= U2 -2gH; where U and V are initial and final velocity and H is height.
Hence H = V2-U2/-2g
=(0)^2- (25)^2/ -2×9.8
= -625/-19.6 =31.89m
Answer:
The reading of Y is -10°.
Explanation:
For scale X, the ice point is 40° and steam point is 120°.
Difference between the two extremes for scales X = 120 - 40 = 80
For scale X, the ice point and steam points are -30° and 130° respectively.
Difference between the two extremes for scales X = 130 - (-30) = 160
Comparing both scales:
One unit of scale X = x
One unit of scale Y = y
Scale X has 80 divisions while scale Y has 160
80x = 160y
x = 2y
50° in scale X = 10x + ice point in X scale
10 divisions in Y scale = 20y
Reading of Y scale = ice point of Y + 20y
= -30° + 20°
= -10°
