Answer:
The coefficient of static friction between the box and floor is, μ = 0.061
Explanation:
Given data,
The mass of the box, m = 50 kg
The force exerted by the person, F = 50 N
The time period of motion, t = 10 s
The frictional force acting on the box, f = 30 N
The normal force on the box, η = mg
= 50 x 9.8
= 490 N
The coefficient of friction,
μ = f/ η
= 30 / 490
= 0.061
Hence, the coefficient of static friction between the box and floor is, μ = 0.061
B is the correct answer, since all others are not true or are based on assumption
It a because I learn it in class today
Answer:
The acceleration of the sprinter is 1.4 m/s²
Explanation:
Hi there!
The equation of position of the sprinter is the following:
x = x0 + v0 · t + 1/2 · a · t²
Where:
x = position of the sprinter at a time t.
x0 = initial position.
v0 = initial velocity.
t = time.
a = acceleration.
Since the origin of the frame of reference is located at the starting point and the sprinter starts from rest, then, x0 and v0 are equal to zero:
x = 1/2 · a · t²
At t = 9.9 s, x = 71 m
71 m = 1/2 · a · (9.9 s)²
2 · 71 m / (9.9 s)² = a
a = 1.4 m/s²
The acceleration of the sprinter is 1.4 m/s²
<span>Ans : The best way to estimate the population density of pine trees in an actual forest is to count the number of trees in a small area and than multiply to find the number in a large area. To get the most accurate estimate, your sample area should be typical of the larger area.
Suppose you count 10 pine tree in 100 sq meters of the forest. If the entire forest were 100 times the size, you would multiply your count by 100 to estimate the total population density, or 1000 (10X100) pine trees.</span>
