Answer:
Explanation:
The wheel and falling student will have common acceleration .
For rotational motion of wheel
Tx r = I α , T is tension in the crank , α is angular acceleration of wheel , I is moment of inertia , r is radius of the wheel.
= I a / r
T = I a / r²
For motion of student
Mg - T = Ma , M is mass of the wheel.
Mg - I a / r² = Ma
Mg = Ma +I a / r²
Mg = (M +I / r²)a
a = Mg / (M +I / r²)
= 51 x 9.8 / ( 51 + 9.6 / .3² )
499.8 / (51+ 106.67 )
= 499.8 / 157.67
= 3.17 m / s².
If time t is taken to fall by 12 m
12 = 1/2 a t²
24 / a = t²
24 / 3.17 =t²
t²= 7.57
t = 2.75 s
velocity to reach sidewalk
v = u + at
= 3.17 x 2.75
= 8.72 m / s
Answer:

Explanation:
Given that,
Charge, 
Revolution = 7 rev
magnetic field, B = 45 mT
Time, t = 1.29 ms
We need to find the mass of the ion. Let m be the mass. The formula for the mass in terms of time period is given by :

So, the mass of the ion is equal to
.
Answer:
29.39 kg
Explanation:
From the question,
W = mg...................... Equation 1
Where W = weight of the cuboid box, m = mass of the cuboid box, g = acceleration due to gravity.
make m the subject of the equation
m = W/g.................. Equation 2
Given: W = 288 N
Constant: g = 9.8 m/s²
Substitute these values into equation 2
m = 288/9.8
m = 29.39 kg
A and C
Imagine u are shooting a laser pointer at a mirror this is pretty much what it is
If the object is not at rest how?