Answer : Textbook, Track shoes and Basketball
Explanation :
The objects can be of three types :
The objects that do not allow to pas through it are called opaque objects.
Out of given options the objects that are opaque are
1. Textbook
2. Track shoes
3. Basketball
Hence, the correct options are (a), (b) and (d)
Answer:
Explanation:
To answer the question, we just need to consider the motion along the horizontal direction.
The component of the initial velocity of the ice skater along the x-direction is:
where u = 2.25 m/s is the initial velocity and is the angle.
The component of the final velocity of the ice skater along the x-direction is
where u = 4.65 m/s is the final velocity and is the angle.
The acceleration along the x-direction is given by
where
t = 120 s is the time
Substituting,
Answer:
h~=371.26m
Explanation:
when an object falls we use the equations of accelerated motion. There is only one that gives distance.
Since we have no initial velocity (started from rest) we can get rid of the (ut) term
where a we substitute g (gravitational acceleration, constant for given heights and almost 9.81m/s^2).
Answer:
The gravitational potential energy of a squirrel is 53.312 J.
Explanation:
We have,
Mass of a squirrel is 0.68 kg
It is placed at a height of 8 m above the ground.
It is required to find the gravitational potential energy of a squirrel. It is possessed by an object due to its position. Its formula is given by :
So, the gravitational potential energy of a squirrel is 53.312 J.
Answer:
a) u_s=0.375
b )v=14.4 m/s
Explanation:
1 Concepts and Principles
Particle in Equilibrium: If a particle maintains a constant velocity (so that a = 0), which could include a velocity of zero, the forces on the particle balance and Newton's second law reduces to:
∑F=0 (1)
2- Particle in Uniform Circular Motion:
If a particle moves in a circle or a circular arc of radius Rat constant speed v, the particle is said to be in uniform circular motion. It then experiences a net centripetal force F and a centripetal acceleration a_c. The magnitude of this force is:
F=ma_c
=m*v^2/R (2)
where m is the mass of the particle F and a_c are directed toward the center of curvature of the particle's path.
<em>3- The magnitude of the static frictional force between a static object and a surface is given by:</em>
f_s=u_s*n (3)
where u_s is the coefficient of kinetic friction between the object and the surface and n is the magnitude of the normal force.
Given Data
R (radius of the car's path) = 170 m
v (speed of the car) = 25 m/s
Required Data
- In part (a), we are asked to find the coefficient of static friction u_s that will prevent the car from sliding.
- In part (b), we are asked to find the speed of the car v if the coefficient of static friction is one-third u_s found in part (a).
Solution:
see the attachment pic
Since the car is not accelerating vertically, we can model it as a particle in equilibrium in the vertical direction and apply Equation (1)
∑F_y=n-mg
= mg (4)
We model the car as a particle in uniform circular motion in the horizontal direction. The force that enables the car to remain in its circular path is the force of static friction at the point of contact between road and tires. Apply Equation (2) to the horizontal direction:
∑F_x=f_s
=m*v^2/R
Substitute for f_s from Equation (3):
u_s=m*v^2/R
Substitute for n from Equation (4):
u_s*mg=m*v^2/R
u_s*g = v^2/R
Solve for u_s:
u_s= v^2/Rg (5)
Substitute numerical values:
u_s=0.375
(b)
The new coefficient of static friction between the tires and the pavement is:
u_s'=u_s/3
Substitute u_s/3 for u_s in Equation (5):
u_s/3=v^2/Rg
Solve for v:
v=14.4 m/s
<u>Answer:</u>
For a. Neutrons and electrons also form an atom.
For b. The element is oxygen which is a non-metal and will form a negative ion while forming ionic bond.
<u>Explanation:</u>
There are 3 subatomic particles which form an atom. These are neutrons, protons and electrons.
Neutrons carry no charge, protons carry positive charge and electrons carry negative charge. Neutrons and protons are present in nucleus and electrons revolve around the nucleus.
The energy which is present between neutrons and protons are nuclear energy and the energy which is present between electrons and protons are electrostatic energy.
In an element, number of protons is always equal to the number of electrons. The atomic number is equal to the number of protons or electrons. The element which has atomic number 8 is Oxygen.
The electronic configuration of this element is
This element requires only 2 electrons to form a stable electronic configuration. An element which gains electron is considered as a non-metal and forms a negative ion because number of electrons increases.