Answer:
5
Explanation:
The light intensity may be defined as the strength of the light or the magnitude of its brightness that a source of light can produce.
The light threshold is the minimum intensity of the light that our eye can detect and the ability to adapt to darkness.
In the context, Daniel wishes to find if can notice the difference in the intensity of the light when he add 5 candles to the set of 50 candles.
He noticed that when he added 5 candles, he could notice the difference in the intensity and when he added less than 5 candles to the set of 50 candles he could not detect.
Thus, the difference threshold for Daniel to detect the change in the intensity of the light is 5 candles.
Answer:
Explanation:
Assuming we have a two hot liquid like 70°C tea and 30°C water, the tea will cool down but not to 30°C but to an equilibrium temperature say 40°C
But in this case, the temperature of the chocolate will drop almost to the room temperature eventually,
The heat in the chocolate will even out into the room temperature and the room will get slightly warmer until the are both in equilibrium temperature. But you won't notice this little change but if you go out of the room, you might notice that change...
So this little fraction is not always notice, so we will still considered it as the room temperature
Answer:
I don't know about the 1st one but An object at rest stays at rest and an object in motion stays in motion at a constant speed and direction unless acted upon by an unbalanced force. Or maybe its moving because the earth is moving and gravity is pulling it with.
2. Speed is the rate at which something or someone is able to move. Instantaneous Speed - the speed at any given instant in time. Average Speed - the average of all instantaneous speeds; found simply by a distance/time ratio.
3. Speed = distance divided by time or 
. Some units for speed can be miles, kilometres, feet, or metres.
4. Speed is the time rate at which an object is moving along a path, while velocity is the rate and direction of an object's movement. Put another way, speed is a scalar value, while velocity is a vector.
Answer:
According to newtons first law of motion an object remains in its state of rest or motion in a straight line unless an external unbalanced forces acts upon it. This is the reason why Newtons first law of motion is often called the LAW OF INERTIA
Answer:
Explanation:
Let the velocity of rocket case and payload after the separation be v₁ and v₂ respectively. v₂ will be greater because payload has less mass so it will be fired with greater speed .
v₂ - v₁ = 910
Applying law of conservation of momentum
( 250 + 100 ) x 7700 = 250 v₁ + 100 v₂
2695000 = 250 v₁ + 100 v₂
2695000 = 250 v₁ + 100 ( 910 +v₁ )
v₁ = 7440 m /s
v₂ = 8350 m /s
Total kinetic energy before firing
= 1/2 ( 250 + 100 ) x 7700²
= 1.037575 x 10¹⁰ J
Total kinetic energy after firing
= 1/2 ( 250 x 7440² + 100 x 8350² )
= 1.0405325 x 10¹⁰ J
The kinetic energy has been increased due to addition of energy generated in firing or explosion which separated the parts or due to release of energy from compressed spring.
