<span>So we want to know which statement is true for the body of mass m=2000kg that is lifted to a height of h=15m in t=15 s. Lets calculate each of the following: Gravity force on the body is F=m*g=2000*9.81=19620 N so a is FALSE. Potential energy of the body when it is lifted to the height of 15 m is Ep=m*g*h=2000*9.81*15=294300 J so b is FALSE. Work to lift the body is: W=Fg*h=2000*9.81*15= Ep=294300 J so c is FALSE. Power P=W/t=294300/15=19620 W So d is TRUE. </span>
Answer:
28
Explanation:
There is a 28 day cycle of the moon phase as it rotates on earths axis.
Answer:
M au = Fs - M g au = upwards acceleration; Fs = scale reading
Fs = M (au + g) scalar quantities where g is positive downwards and au is positive upwards - Fs is the net force acting on the person
If the acceleration is zero Fs = M g and the scale reads the persons weight
If the elevator is decelerating then au is negative and the scale reading Fs = (g - au) M and the scale reading is less than the weight of the person
Answer:
49.63 degree
Explanation:
thickness of glass slab, t = 0.6 cm
angle of incidence = 59 degree
Let r be the angle of refraction
The refractive index of glass, ng = 3/2
refractive index of water, nw = 4/3
refarctive index of glass with respect to water = ng / nw = 3 /2 ÷ 4 /3 = 9 / 8
So, by use of Snell's law
Refractive index of glass with respect to water = Sin i / Sin r
9 / 8 = Sin 59 / Sin r
9 / 8 = 0.857 / Sin r
Sin r = 0.7619
r = 49.63 degree