We can solve the problem by using Ohm's law, which states that an Ohmic conductor the following relationship holds:

where

is the potential difference applied to the resistor
I is the current flowing through it
R is the resistance
In our problem, I=4.00 A and

, so the potential difference is
Answer:0.6kw
Explanation:
Power=force×velocity
Power=20×30=600w
In kw it's going to be 600/1000=0.6kw
Answer:
A
Explanation:
The roller coaster is stationary so the kinetic energy would be zero, but it is at the top of ramp so the potential energy would be high as its gravitational so it would have to be A
Answer:

Explanation:
As we know that if the object is placed on the inclined plane then the force of friction on the object is counterbalanced by the component of the weight of the object along the inclined plane.
So we can say

now if we increase the inclination of the plane then the component of the weight weight along the inclined plane will increase and hence the friction force will also increase.
As we know that the limiting value or the maximum value of friction force at the static condition is given by


so we have

so we will have

so now we have

so maximum possible angle of the inclined plane is

Answer:
a). 53.75 N and 101.92 N
b). 381.44 N and 723.25 N
Explanation:

a).
ρ
,
, 

b).
ρ
,
, 
