Answer:
Explanation:
Electric field between plates of a parallel plate capacitor is uniform .
In a uniform electric field , relation between electric field and potential gradient is as follows
electric field = potential gradient [ E = - dV / dl ]
in the given case ,
dV = 51 V ,
dl = 4 cm
= 4 x 10⁻² m
E = 51 / 4 x 10⁻²
= 12.75 x 10² V / m
= 1275 V / m
You can use mostly anything as long as it is circular. Depending on how big it is, you could use sturdy paper plates and use a stick/rod and tape to hold it together, or you could use bottle caps if the car you are trying to make is really small.
Answer:
Option A
Explanation:
This can be explained based on the conservation of energy.
The total mechanical energy of the system remain constant in the absence of any external force. Also, the total mechanical energy of the system is the sum of the potential energy and the kinetic energy associated with the system.
In case of two stones thrown from a cliff one vertically downwards the other vertically upwards, the overall gravitational potential energy remain same for the two stones as the displacement of the stones is same.
Therefore the kinetic energy and hence the speed of the two stones should also be same in order for the mechanical energy to remain conserved.
Answer:
20 N
Explanation:
In air, the normal force is equal to the weight.
∑F = ma
N − mg = 0
N = mg
Submerged in water, the normal force is equal to the weight minus the buoyant force:
∑F = ma
B + N − mg = 0
N = mg − B
Plugging in values:
80 N = 100 N − B
B = 20 N
Answer:
the correct answer is C, E’= 4E
Explanation:
In this exercise you are asked to calculate the electric field at a given point
E = 
indicates that the field is E for r = 2m
E = 
(1)
the field is requested for a distance r = 1 m
E ’= k \frac{q}{r'^2}
E ’= k q / 1
from equation 1
4E = k q
we substitute
E’= 4E
so the correct answer is C
