She ran for 3s
Put 18/6 because in order to find how long she ran for you need to divide the distance by the meters ran, once you do that you will get 3.
To determine the force that acts on the mass, just multiply the mass by the gravitational field. Using the given data,
F = (2.50 kg)(14 N/kg) = 35 N
Therefore, the force that acts on the mass is equal to 35 N.
Answer:
<em>n =1.33 revolutions</em>
Explanation:
<u>Uniform Circular Motion</u>
The angular speed can be calculated in two different ways:

Where:
v = tangential speed
r = radius of the circle described by the rotating object
Also:

Where:
f = frequency
Solving for f:

Since the frequency is calculated when the number of revolutions n and the time t are known:

We can solve for n:
n=f.t
The particle moves in a circle of r=90 m with a speed v=25 m/s. Thus the angular speed is:


Now we calculate f:


Calculating the number of revolutions:
n = 0.04421*30
n =1.33 revolutions