Answer:
The given statement is false.
Explanation:
The spherical mirrors are the mirror that are a part of a sphere. Concave and convex mirrors are two types of spherical mirrors.
A concave mirror always forms real and inverted image. A convex mirror forms real and virtual images.
For concave mirror, the value of magnification is less that 1. Also, the focal length is negative for concave mirrors.
So, the given statement is false as a concave mirror always forms a real and inverted image. Hence, this is the required solution.
Answer:
The air is contained at a high pressure in the tube. When it escapes from a small orifice, it suddenly expands. A large amount of its heat is absorbed in the process of expansion resulting in considerable fall in its temperature. This is why the escaping air feels cold.
Answer:
The magnitude of induced emf is 5.4 V
Explanation:
Given:
Magnetic field 
T
Area of loop 
Time take to reduce loop to zero 
sec
To find induced emf we use faraday's law,
Induced emf is given by,
Here minus sign shows lenz law, for finding magnitude of emf we ignore it.
Where 
Put the value of flux and find induced emf,
V
Therefore, the magnitude of induced emf is 5.4 V
Answer:
a) k = 2231.40 N/m
b) v = 0.491 m/s
Explanation:
Let k be the spring force constant , x be the compression displacement of the spring and v be the speed of the box.
when the box encounters the spring, all the energy of the box is kinetic energy:
the energy relationship between the box and the spring is given by:
1/2(m)×(v^2) = 1/2(k)×(x^2)
(m)×(v^2) = (k)×(x^2)
a) (m)×(v^2) = (k)×(x^2)
k = [(m)×(v^2)]/(x^2)
k = [(3)×((1.8)^2)]/((6.6×10^-2)^2)
k = 2231.40 N/m
Therefore, the force spring constant is 2231.40 N/m
b) (m)×(v^2) = (k)×(x^2)
v^2 = [(k)(x^2)]/m
v = \sqrt{ [(k)(x^2)]/m}
v = \sqrt{ [(2231.40)((1.8×10^-2)^2)]/(3)}
= 0.491 m/s
<span>A baseball speeds up as it falls through the air.
Yes. Forces on the balloon are unbalanced.
The balloon is speeding up, so we know that the downward force
of gravity is stronger than the upward force of air resistance.
A soccer ball is at rest on the ground.
No. The ball is not accelerating, so we know that the forces on it
are balanced.
The downward force of gravity on the ball and the upward force
of the ground are equal.
An ice skater glides in a straight line at a constant speed.
No. The skater's speed and direction are not changing, so he is not
accelerating. That tells us that the forces on him are balanced.
A bumper car hit by another car moves off at an angle.
Yes. The direction in which the car was moving changed.
That's acceleration, so we know that the forces on it are unbalanced,
at least at the moment of impact.
A balloon flies across the room when the air is released.
Yes. The balloon was not moving. But when the little nozzle was
opened, it started to zip around the room. So its speed changed.
And, as it goes bloozing around the room, its direction keeps changing too.
There's a whole lot of acceleration going on, so we know the forces on it
are unbalanced.</span>
