Answer:

Explanation:
The torque exerted is given by

where
is the force applied
d = 3.10 cm = 0.031 m is the length of the lever arm
Substituting,

The equivalent of Newton's second law for rotational motion is:

where
is the net torque
I is the moment of inertia
is the angular acceleration
Solving the equation for I, we find

Answer:
a) t= 4.81 s,and t= 23.51.
b)d=6.88 m
c)v=4.8 m/s
Explanation:
Acceleration of train ,a= 0.6 m/s²
u = 0 m/s
Your speed ,V= 8.5 m/s
Lets take after t time he you catch the train
Distance travel by train in t time
----------1
d= V ( t- 4)
d= 8.5 ( t- 4) --------2
By equating equation 1 and 2
0.3 t² = 8.5 ( t- 4)
0.3 t² -8.5 t + 34 = 0
t= 4.81 s and t= 23.51
It means that you will catch train after t= 4.81 s,and t= 23.51.
t=23.51 sec means that you will catch the train after 23.51 sec also because acceleration of train is low.
Distance travel
d= 8.5 ( t- 4)
t= 4.81 s
d= 8.5 ( 4.81- 4) m
d=6.88 m
Lets speed = v
0.3 t² = v ( t- 4)
0.3 t² - v t + 4 v = 0
To have one solution

D= 0 Should be zero.
v²- 4 x 0.3 x 4 v
v = 4 x 0.3 x 4
v=4.8 m/s
It's 61.5m
by solving simultaneously equations
29+d = 6t (bear)
d=4.1t (tourist)
The answer is B.
t = Vy / g
t =( 19 x sin21 ) / 9.8 = 0.69s