Answer:
mass = 0.18 [kg]
Explanation:
This is a classic problem where we can apply the definition of density which is equal to mass over volume.
![density = \frac{mass}{volume} \\\\where:\\volume = 1 [m^3]\\density = 0.18[kg/m^3]](https://tex.z-dn.net/?f=density%20%3D%20%5Cfrac%7Bmass%7D%7Bvolume%7D%20%5C%5C%5C%5Cwhere%3A%5C%5Cvolume%20%3D%201%20%5Bm%5E3%5D%5C%5Cdensity%20%3D%200.18%5Bkg%2Fm%5E3%5D)
mass = 0.18*1
mass = 0.18 [kg]
A tennis player who is recovering from an ankle injury and is not allowed to change directions can maintain her cardio fitness level by using the rowing machine, the stationary bike with one leg, or swimming. These activities do not require a change in direction. These activities will not give strain to the injured part.
Answer:
F = 9.81 [N]
Explanation:
To solve this problem we must use Newton's third le which tells us that the sum of forces on a body that remains static must be equal to one resulting from these forces in the opposite direction.
Let's perform a summation of forces on the vertical axis-y to determine the normal force N.
∑F = 0 (axis-y)

where:
m = mass = 4 [kg]
g = gravity acceleration = 9.81 [m/s²]
![N - (4*9.81)=0\\N = 39.24 [N]](https://tex.z-dn.net/?f=N%20-%20%284%2A9.81%29%3D0%5C%5CN%20%3D%2039.24%20%5BN%5D)
Now we know that the frictional force can be calculated using the following equation.
f = μ*N
where:
f = friction force [N]
μ = friction coefficient = 0.25
N = normal force = 39.24 [N]
Now replacing:
![f = 0.25*39.24\\f = 9.81[N]](https://tex.z-dn.net/?f=f%20%3D%200.25%2A39.24%5C%5Cf%20%3D%209.81%5BN%5D)
Then we perform a sum of forces on the X-axis equal to zero. This sum of forces allows us to determine the minimum force to be able to move the object in a horizontal direction.
∑F = 0 (axis-x)
![F-f=0\\F-9.81=0\\F= 9.81[N]](https://tex.z-dn.net/?f=F-f%3D0%5C%5CF-9.81%3D0%5C%5CF%3D%209.81%5BN%5D)
If the coefficient was smaller, a smaller force (F) would be needed to start the movement, this can be easily seen by replacing the value of 0.25, by smaller values, such as 0.1 or 0.05.
If the coefficient were larger, a larger force would be needed.
The second ball traveled a greater distance when compared to the first ball because the second ball spent more time in motion.
The given parameters;
- time of fall of the first ball, t = 1 s
- time of fall of the second ball, t = 3 s
The distance traveled by each ball is calculated using the second equation of motion as shown below.
The distance traveled by the first ball is calculated as follows;

The distance traveled by the second ball is calculated as follows;

Thus, the second ball traveled a greater distance because it spent more time in motion.
Learn more here:brainly.com/question/5868480