Answer:
The elevator must be <u>accelerating upward</u> as the net force acting is upward.
Explanation:
Given:
Original weight of the student,
Reading on the spring scale is the normal reaction by the scale on the student and is given as,
The normal reaction acts in the upward direction while the weight of the student acts vertically downward.
Now, the magnitude of the normal reaction is greater than the magnitude of the weight. Therefore, the net force acting on the student is given as:
Therefore, the net force is acting vertically upward.
Now, as per Newton's second law, the direction of the net acceleration acting on a body is the same as the direction of the net force acting on it.
Thus, the elevator must be accelerating upward as the net force acting is upward.
Answer:
V = 6.55*10^{-6} v
Explanation:
The number density can be determined by using below formula:
where,
B is uniform magnetic field 0.74
i is current 18 A
V is hall potential difference
l is thickness 150 MICRO METER
e is electron charge 1.6 *10^{-19} C
therefore V can be determined as
V = 6.55*10^{-6} v
Answer:
The length of the train in the frame of the lecture room is 40.59 m.
Explanation:
Given that,
Speed = 0.894 c
Original length = 90.6 m
We need to calculate the length of the train in the frame of the lecture room
Using formula of length contraction
Where, =original length
v = speed of train
Put the value into the formula
Hence, The length of the train in the frame of the lecture room is 40.59 m.
Answer:
Area of the plates of a capacitor, A = 0.208 m²
Explanation:
It is given that,
Charge on the parallel plate capacitor,
Electric field, E = 3.1 kV/mm = 3100000 V/m
The electric field of a parallel plates capacitor is given by :
A = 0.208 m²
So, the area of the plates of a capacitor is 0.208 m². Hence, this is the required solution.