Heat comes from the movement of molecules so it's B
Answer:

Explanation:
given,
traffic light weight = 100 N
angle at which the rope is supported = 30°
vertical component of force = ?







Answer:
7.39 m/s
Explanation:
Applying
K.E = 1/2mv²..................... Equation 1
Where K.E = Kinetic Energy, m = mass of the ball, v = velocity of the ball.
Make v the subject of the equation
v = √(2K.E/m)................. Euqation 2
From the question,
Given: K.E = 30 J, m = 1.1kg
Substitute these values into equation 2
v = √(2×30/1.1)
v = √54.54
v = 7.39 m/s
B or D, one of these are the correct answer