We have two equation for the mirror:
Index i denotes an image, and index 0 denotes the object.
In our case, magnification is 0.25:
We plug this back into the first equation:
Answer:
Explanation:
Moment of inertia of toy top = 3 x 10⁻² kgm²
Torque created = F x r
= .30 x 2.5 x 10⁻² N m
Torque = moment of inertia x angular acceleration
angular acceleration = .3 x 2.5 x 10⁻² / 3 x 10⁻²
α = .25 radian /s²
Angular displacement in 5 revolution θ = 5 x 2π = 10π radian
θ = ω₀t + 1/2 α t²
initial angular velocity ω₀ = 0
10π = 1/2 α t² = .5 x .25 t²
t² = 251.2
t = 15.85 s
Answer:
2. The total initial angular momentum is non-zero and total angular momentum is conserved.
Explanation:
Let the mass of the boy be m and v be his velocity . His linear momentum
p = mv , If R be the radius of the circular path of merry go round . When the boy jumps on the merry gold round , he adds an angular momentum to the system .
Angular momentum of the boy with respect to the center of merry go round
L = r x p = r p sin90.
= r p
= m v r
This is the initial angular momentum of the system of boy and merry go round .
Total final angular momentum of the system will also be equal to initial angular momentum , according to law of conservation of angular momentum , since no external torque is acting on the system.
Answer:
The acceleration of the refrigerator is
Explanation:
The expression of the equation of the net force acting on the refrigerator is as follows;
F-f= ma
Here, F is the applied force, f is the force of friction, m is the mass and a is the acceleration.
It is given in the problem that you're having a hard time pushing a refrigerator having mass 355 kg across the kitchen floor. The force of your own push is 993 N. The force of friction opposing your own push is 973 N.
Put F= 993, f= 973 N and m = 355 kg in the above expression of the equation to calculate the acceleration of the refrigerator.
993 - 973 = (355)a
20 = 355 a
Therefore, the acceleration of the refrigerator is .