Unlike acceleration and velocity, speed does not need to specify the direction of motion. Speed is a scalar quality.
Answer:
82.4 cm
Explanation:
The object and screen are kept fixed ie the distance between them is fixed and by displacing lens between them images are formed on the screen . In the first case let u be the object distance and v be the image distance
then ,
u + v = 184 cm
In the second case of image formation , v becomes u and u becomes v only then image formation in the second case is possible.
The difference between two object distance ie( v - u ) is the distance by which lens is moved so
v - u = 82.4 cm
Explanation: Newton's first law of motion states that a body at rest remains at rest, or, if in motion, remains in motion at a constant velocity unless acted on by a net external force. This is also known as the law of inertia. Inertia is the tendency of an object to remain at rest or remain in motion.
Use pythagorean's theorem for this, with 7 as a and 5 as b. pythagorean's theorem says that a^2 + b^2 = c^2, so 7^2 * 5^2 = c^2. this gives you 49 + 25 = c^2, so 74 = c^2. c = sqrt 74, which is approximately 8.60 km
a. 25 joules of work is done by the object.
Explanation:
According to the work-energy theorem, the work done ON an object is equal to the change in kinetic energy of the object, therefore:

where
is the final kinetic energy of the car, with
m = 2 kg being the mass of the car
v = 0 is the final speed of the car (brought to rest)
is the initial kinetic energy of the car, with
u = 5 m/s being the initial speed of the car
Substituting numbers, we find:

The negative sign means that the work done ON the car is negative: this means therefore that the work has been actually done BY the car. In fact, the car has lost its kinetic energy: this means that it has done work on the surrounding, converting its kinetic energy into other forms of energy.
Learn more about work and kinetic energy:
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