Answer:
but for helping we need yr ques nd they r not here
Answer: 26.67 m/s
Explanation:
Given
Length traveled by the ball 
Time taken to reach the goal post is 
Initial velocity 
Using the second equation of motion

Now using

The velocity of ball will be 26.67 m/s
Answer:
Total time = 10.667 seconds
Explanation:
For the first 12m
V² = u² + 2as
10.5² = 0² + 2a(12)
110.25 = 24a
a = 4.59375 m/s²
V = u + at
10.5 = 0 + 4.59375t
t = 10.5/4.59375
t = 2.286 seconds
For the remaining race
100-12 = 88m
He travels at a constant speed for 88m
S = ut + 1/2(at²)
But a = 0
S = ut
88= 10.5t
t = 88/10.5
t = 8.38.seconds
Total time = 2.286 + 8.381
Total time = 10.667 seconds
Answer:

Explanation:
Since there is no friction angular momentum is conserved. The formula for angular momentum thet will be useful in this case is
. If we call 1 the situation when the student is at the rim and 2 the situation when the student is at
from the center, then we have:

Or:

And we want to calculate:

The total moment of inertia will be the sum of the moment of intertia of the disk of mass
and radius
, which is
, and the moment of intertia of the student of mass
at position
(which will be
or
) will be
, so we will have:

or:

which for our values is:

Answer:
The magnetic force on the wire at the moment is 2 micro-Newton/(Ampere-meter)
Explanation:
Formula for magnetic force is F = qvB*sin(theeta)
and B = μ*I / 2*pi*r
where
q = charge in coulomb
v = velocity
B = magnetic field strength
μ = permeability of free space
I = current
so from here we get B = (4*pi*10^(-7))(5) / 2*pi*0.01 = 0.0001-T
now ,
F = (2mC)*(10)*0.0001*sin(90)
F = 2 micro-Newton/(Ampere-meter)