Answer:
C. At a particular instant
Explanation:
Speed is the defined as the ratio between the distance covered by an object and the time taken:
where d is the distance and t the time.
However, there are two possible measurements of speed:
- Average speed: this is the speed measured over a non-zero time interval (for example: a car moving 100 metres in 5 seconds; its average speed is
- Instantaneous speed: this is the speed of an object measured at a particular instant in time, so for a time interval that tends to zero. So, in the previous example, the average speed is 20 m/s but the instantaneous speed of the car at various instants of time can be different from that value.
Answer:
(a) 
(b) 
Explanation:
(a) The surface current density of a conductor is the current flowing per unit length of the conductor.
Considering a wire, the current is uniformly distributed over the circumferenece of the wire.
The radius of the wire = a
The surface current density
(b) The current density is inversely proportional
......(1)
k is the constant of proportionality
........(2)
substituting (1) into (2)
substitute
Answer:
The correct answer is the Convex lens. An image is formed when a ray of light coming from a point intersects at another point. The image is formed by the real intersection of light. The image is formed by the virtual intersection of Light.
here is the site : textbook.com
Force = mass × acceleration
To find acceleration, we can divide the speed by the time it took:
acceleration = 2.40×10^7 / 1.8×10^-9
acceleration = 1.33×10^16
the mass is equal to the mass of an electron
force = (9.11×10^-31)(1.33×10^16)
force = 1.21×10^-14 N
Answer : I hope this helps !
The Effort Force is the force applied to a machine. Work input is the work done on a machine. The work input of a machine is equal to the effort force times the distance over which the effort force is exerted.
