In the second 30 mins, the speed should be 20 + 1.5 = 21.5 km/h
So S = 21.5 * 30/60 = 10.75 km
The mass of a radioactive element at time t is given by

where

is the mass at time zero, while

is the half-life of the element.
In our problem,

, t=121.0 s and

, so we can find the initial mass

:
Answer:

Explanation:
We know that the magnetic Field of the Earth is 50\mu T, so the equation for
Hall effect voltage und magnetic field are defined as,


So,



Answer:
The voltage is 
Explanation:
From the question we are told that
The duty cycle is p = 65% = 0.65
The on - state voltage is 
Generally the average DC voltage is mathematically represented as

=> 
=> 
Answer:
the tangential velocity of the student is 4.89 m/s.
Explanation:
Given;
the radius of the circular path, r = 3.5 m
duration of the motion, t = 4.5 s
let the student's tangential velocity = v
The tangential velocity of the student is calculated as follows;

Therefore, the tangential velocity of the student is 4.89 m/s.