If the object is moving in a straight line at a constant speed, then that's
the definition of zero acceleration. It can only happen when the sum of
all forces (the 'net' force) on the object is zero.
And it doesn't matter what the object's mass is. That argument is true
for specks of dust, battleships, rocks, stars, rock-stars, planets, and
everything in between.
Answer:
Max speed = 
Max acceleration = 
Explanation:
Given the description of period and amplitude, the SHM could be described by:

and its angular velocity can be calculated doing the derivative:

And therefore, the tangential velocity is calculated by multiplying this expression times the radius of the movement (3 m):
and is given in m/s.
Then the maximum speed is obtained when the cosine function becomes "1", and that gives:
Max speed = 
The acceleration is found from the derivative of the velocity expression, and therefore given by:

and the maximum of the function will be obtained when the sine expression becomes "-1", which will render:
Max acceleration = 
Answer:
69.68 N
Explanation:
Work done is equal to change in kinetic energy
W = ΔK = Kf - Ki = 
W = 
where m = mass of the sprinter
vf = final velocity
vi = initial velocity
W = workdone
kf = final kinetic energy
ki = initial kinetic energy
d = distance traveled
Ftotal = total force
vf = 8m/s
vi= 2m/s
d = 25m
m = 60kg
inserting parameters to get:
W = ΔK = Kf - Ki = 



= 39.7
we know that the force the sprinter exerted F sprinter, the force of the headwind Fwind = 30N

I = E / R
If the resistors are in series, the current is 0.3 Amperes.
If the resistors are in parallel, the current is 1.25 Amperes.