Answer:
Explanation:
Given
length of window 
time Frame for which rock can be seen is 
Suppose h is height above which rock is dropped
Time taken to cover 
so using equation of motion

where y=displacement
u=initial velocity
a=acceleration
t=time
time taken to travel h is

Subtract 1 and 2 we get


and from equation 
so 

and 
so 



substitute the value of
in equation 2


Answer:
Her error was that she did not subtract 12 from 8 correctly
Explanation:
Jackie did 8-12 instead of 12-8
Since U=0,
h=1/2gt^2 (h= ut+1/2gt^2, U=0)
h=1/2*10*4*4
h=80m
Answer:
3.82 Ns
Explanation:
Time varying horizontal Force is given as
F(t) = A t⁴ + B t²
F(t) = 4.50 t⁴ + 8.75 t²
Impulse imparted is given as





RT = R1 R2/ R1 + R2
R1 = R2 = 2k ohm
RT = R/2 = 2k/2 = 1k ohm