Answer:
D. The cart is moving at a constant speed or velocity
Explanation:
Equilibrium is a state of body in which it is either at rest or moves with uniform velocity. The sum of forces acting on such a body is always zero and the sum of all the torques acting on it is also zero.
There are two types of equilibrium as follows:
Static Equilibrium: When a body is at rest it is said to be in static equilibrium.
Dynamic Equilibrium: When a body is moving with constant velocity, then it is said to be in dynamic equilibrium.
Hence, the correct option here will be:
<u>D. The cart is moving at a constant speed or velocity</u>
Answer:
The velocity of the photo electron is
.
Explanation:
Given that,
Supplied energy, 
Minimum energy of the electron to escape from the metal, 
We need to find the velocity of the photo electron. The energy supplied by the photon is equal to the sum of minimum escape energy and the kinetic energy of the escaping electron. So,

The formula of kinetic energy is given by :

So, the velocity of the photo electron is
.
The spring scale will read 559 Newton's or 125.7 pounds.
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.