Answer
given,
Weight of the child = 110 N
length of the swing,L = 2 m
now, calculating the potential energy when the string is horizontal
Potential energy = m g h
now, h = L (1 - cos θ) where θ is the angle made by the string with the vertical.
PE = m g L (1 - cos θ)
when rope is horizontal θ = 90°
PE = 110 x 2 (1 - cos 90°)
PE = 220 J
now, calculating potential energy when string made 25° with horizontal
PE = m g L (1 - cos θ)
when rope is horizontal θ = 25°
PE = 110 x 2 (1 - cos 25°)
PE = 20.61 J
The answer is letter C. 1.2 10^-11 N up
Solution:
F= Bqvsin(theta)
theta = sin 90 = 1
F= 1.4 T * 1.6x10^-19 * 5.2x10^7 ms^-1
F= 1.16 x 10^-11 N
Then the direction is upward.
Answer:
Dear user,
Answer to your query is provided below
Acceleration is zero because of no change in velocity.
Explanation:
Remember that velocity is a vector quantity and a vector can change in 3 ways
•Magnitude only
•Direction only
•Both magnitude and direction.
Now the magnitude of velocity (speed) can stay constant while the direction is changing. This is the case in circular motion.
In the question above, it is mentioned that the girl is moving along a straight road. Therefore no change in direction of velocity.
Answer:
if the two polarizers have the same direction the transmitted light is 50% of the incident and if the two polarizers are at 90º the transmitted light is zero
Explanation:
The incident light is generally random, that is, it does not have a polarization plane, when the first polarized stops by half, this already polarized light arrives at the second polarizer and the causticity passes
I = I₀ cos² θ
therefore if the two polarizers have the same direction the transmitted light is 50% of the incident and if the two polarizers are at 90º the transmitted light is zero
