Answer:
<em>The force of kinetic friction between Kiera and the floor is 9.24 N</em>
Explanation:
<u>Friction Force</u>
When an object is moving and encounters friction in rough surfaces, it loses acceleration and/or velocity because the friction force opposes motion.
The friction force when an object is moving on a horizontal surface is calculated by:
Where μ is the coefficient of static or kinetics friction and N is the normal force.
If no forces other then the weight and the normal are acting upon the y-direction, then the weight and the normal are equal in magnitude:
N = W
Thus, the friction force is:
Kiera, the W=330 N girl steps in water that has a coefficient of friction of μ=0.028 with the floor.
The kinetic friction force is:
Fr = 0.028*330
Fr = 9.24 N
The force of kinetic friction between Kiera and the floor is 9.24 N
Answer:
The velocity of the ball is 0.92 m/s in the downward direction (-0.92 m/s).
Explanation:
Hi there!
The equation for the velocity of an object thrown upward is the following:
v = v0 + g · t
Where:
v = velocity of the ball.
v0 = initial velocity.
g = acceleration due to gravity (-9.8 m/s² considering the upward direction as positive).
t = time.
To find the velocity of the ball at t = 0.40 s, we have to replace "t" by 0.40 s in the equation:
v = v0 + g · t
v = 3.0 m/s - 9.8 m/s² · 0.40 s
v = -0.92 m/s
The velocity of the ball is 0.92 m/s in the downward direction (-0.92 m/s).
Answer:
The object will not move.
Explanation:
If nothing pushes against it it will not move. If its not on a slant it will not move.
Answer:
• riding on a Ferris wheel whose entrance and exit are the same
• walking around the block, starting from and ending at the same house
• running exactly one lap around a racetrack
Explanation:
Displacement simply means the.change in position of an object. In a situation whereby the initial and final position are thesame, the displacement will be zero.
The statements that describe a situation with a displacement of zero include:
• riding on a Ferris wheel whose entrance and exit are the same
• walking around the block, starting from and ending at the same house
• running exactly one lap around a racetrack
Answer:
The mass percentage of calcium nitrate is 31.23%.
Explanation:
Let the the mass of calcium nitrate be x and mass of potassium chloride be y.
Total mass of mixture = 19.12 g
x + y = 19.12 g..(1)
Mass of solvent = 149 g = 0.149 kg
Freezing point of the solution,
= -5.77 °C
Molal freezing constant of water = 1.86 °C/m =1.86 °C/(mol/kg)
The van't Hoff factor contribution by calcium nitrate is 3 and by potassium chloride is 2.So:
i = 3
i' = 2
Freezing point of water = T = 0°C
On solving we get:
....(2)
Solving equation (1)(2) for x and y:
x =5.973 g
y = 13.147 g
Mass percent of 
in the mixture:
The mass percentage of calcium nitrate is 31.23%.
