Answer:
Length of shadow cast by hand= 5.0 cm
Step-by-step explanation:
With the hand inclined at an angle θ=30.0∘ above horizontal, it can be imagined to form part of a right angled triangle that has the following parts
vertical screen=vertical part of the triangle where we cast the shadow of the hand
The hand=the hypotenuse side
The horizontal = side to which the hand makes the 30.0° angle
By trigonometric relationship
Sin θ°= Opposite/hypotenuse
Sin θ° = (Shadow cast by hand)/(Length of hand)
Sin 30° = ( length of shadow cast by hand)/10cm
or 0.5 = (length of shadow cast by hand)/10cm
Length of shadow cast by hand= 0.5 × 10cm = 5.0 cm