Answer:
25 m/s
Explanation:
First of all, we can find the acceleration the object by using Newton's second law of motion:
where
F = 20.0 N is the net force applied on the object
m = 4.0 kg is the mass of the object
a is its acceleration
Solving for a, we find
Now we know that the motion of the object is a uniformly accelerated motion, so we can find its final velocity by using the following suvat equation:
where
v is the final velocity
u = 0 is the initial velocity
is the acceleration
t = 5 s is the time
By substituting,
Answer:
799.54 ft
Explanation:
Linear thermal expansion is:
ΔL = α L₀ ΔT
where ΔL is the change in length,
α is the linear thermal expansion coefficient,
L₀ is the original length,
and ΔT is the change in temperature.
Given:
α = 1.2×10⁻⁵ / °C
L₀ = 800 ft
ΔT = -17°C − 31°C = -48°C
Find: ΔL
ΔL = (1.2×10⁻⁵ / °C) (800 ft) (-48°C)
ΔL = -0.4608
Rounded to two significant figures, the change in length is -0.46 ft.
Therefore, the final length is approximately 800 ft − 0.46 ft = 799.54 ft.
Explanation:
Let the speeds of father and son are 
. The kinetic energies of father and son are 
. The mass of father and son are 
(a) According to given conditions, 
And 
Kinetic energy of father is given by :
.............(1)
Kinetic energy of son is given by :
...........(2)
From equation (1), (2) we get :
..............(3)
If the speed of father is speed up by 1.5 m/s, so the ratio of kinetic energies is given by :
Using equation (3) in above equation, we get :
(b) Put the value of 
in equation (3) as :
Hence, this is the required solution.
Draw a free body diagram to show which forces act in the x and y directions. The x component equation is σfx = 0. The σfx being all the forces acting in the x direction.
Answer:
The circumference of the Earth is 24818.58 miles
Explanation:
Analysis conceptual : The formula of the circumference is the following:
L= π*D Formula (1)
Where:
L : is the length of the circumference in miles (mi)
π : is the constant
D : is the diameter of the circumference in miles (mi)
Known data
π = 3.1416
D= 7900 miles: Diameter of the Earth
Problem development
We apply the formula 1 to calculate the circumference of the Earth (L):
L= π*7900 miles
L= 24818.58 miles
