Light rays change direction when they hit a mirror. The phenomenon is known as reflection. Light rays travels in a straight light. They strike the surface of the mirror at a particular angle called incident angle. It is the angle between the ray and normal at the point of contact. The rays leaves the surface making the same angle with the normal called reflection angle but in different direction.
Uncertainty means that your result may be very random, so you can't trust the first or second or so observation, making several samples critical for accuracy. <span />
Answer:
v_f = 3 m/s
Explanation:
From work energy theorem;
W = K_f - K_i
Where;
K_f is final kinetic energy
K_i is initial kinetic energy
W is work done
K_f = ½mv_f²
K_i = ½mv_i²
Where v_f and v_i are final and initial velocities respectively
Thus;
W = ½mv_f² - ½mv_i²
We are given;
W = 150 J
m = 60 kg
v_i = 2 m/s
Thus;
150 = ½×60(v_f² - 2²)
150 = 30(v_f² - 4)
(v_f² - 4) = 150/30
(v_f² - 4) = 5
v_f² = 5 + 4
v_f² = 9
v_f = √9
v_f = 3 m/s
Answer:
539.5°
Explanation:
33.3 revolutions per minute
1 revolution = 360°
1 minute = 60 seconds
hence
33.3 revs ----> 1 minute = 60 seconds
X revs -----------> 2.70 seconds
X = (33.3 x 2.7)÷60 = 1.4985 revolutions in 2.70 seconds
1.4985 revolutions = 1.4985 x 360 = 539.46
which is approximately 539.5°
