Answer:
Explanation:
mass of the fellow ( m ) = 66kg
acceleration of fellow a
v = u + at
4.5 = 0 + a x 2
a = 4.5 /2
= 2.25 m / s²
Net force acting on fellow in upward direction by the surface of elevator
R - mg where R is reaction force of the surface of the elevator
Applying Newton's law of motion
R - mg = ma
R = m (g +a )
= 66 x ( 9.8 + 2 )
= 778.8 N
This will be the scale reading .
Answer:
E = 5291.00 N/C
Explanation:
Expression for capacitance is

where
A is area of square plate
D = DISTANCE BETWEEN THE PLATE




We know that capacitrnce and charge is related as


v = 9.523 V
Electric field is given as

= 
E = 5291.00 V/m
E = 5291.00 N/C
Answer: Rock require larger drag force and to achieve it rock need to move at a very high terminal velocity.
Explanation: Terminal velocity is defined as the final velocity attained by an object falling under the gravity. At this moment weight is balanced by the air resistance or drag force and body falls with zero acceleration i.e. with a constant velocity.
Case 1: Terminal velocity of a piece of tissue paper.
The weight of tissue paper is very less and it experiences an air resistance while falling downward under the effect of gravity.
Downward gravitational force, F = mg
Upward air resistance or friction or drag force will be 
So, paper will attain terminal velocity when mg =
Case 2: Rock is very heavy and require larger air resistance to balance the weight of rock relative to the tissue paper case.
Downward force on rock, F = Mg
Drag force =
Rock will attain terminal velocity when Mg =
Mg > mg
so,
>
And rock require larger drag force and to achieve it rock need to move at a very high terminal velocity.
Answer: A while driving a car. It is unsafe
When an elevator is accelerating downward, the normal force is equal to mg-ma (hence you feel a little lighter when accelerating downwards)
Therefore, the upward force of the elevator floor on the person must be less than 750N