I recently did this topic in science class - the answer is A ;)
Answer:
Statement 1 and 3 are correct.
Explanation:
1. The mass moves downward, so the net acceleration of the block is straight downward.
2.The mass is sliding through the globe, so only the force of gravity is acting on the mass which pulls it in downward direction. The force of gravity has two components [mg sin∅] and [mg cos∅].
Answer:
zero
Explanation:
q = 6.4 nC = 6.4 x 1 0^-9 C
d = 16 cm = 0.16 m
r = 16 / 2 = 8 cm = 0.08 m
Electric field at P due to the charge placed at A
Ea = k q / r^2
Ea = ( 9 x 10^9 x 6.4 x 10^-9) / (0.08 x 0.08) Towards right
Ea = 9000 Towards right
Electric field at P due to the charge placed at B
Eb = k q / r^2
Eb = ( 9 x 10^9 x 6.4 x 10^-9) / (0.08 x 0.08) Towards left
Eb = 9000 Towards left
The magnitude of electric field is same but teh direction is opposite, so the resultant electric field at P is zero.
A. Closed. This is because the circuit can flow without interruption.
Some guidance notes which may help.To calculate the current flow, Ohm's law can be used. This can be written as current=voltage/resistance, or I=V/R. V is 1.5V.R for the copper wire quoted would be calculated as R = resistivity x length/cross sectional area. The area would be calculated from the formula area = pi x diameter squared/4So, R=resistivity x length divided by (pi x diameter squared/4)Until is the resistivity of copper is known, that's about as far as can be gone.Any further questions, please ask.