Answer:
B.7.5m/s2
Explanation:
average acceleration=change invelocity/time taken
a=(60-30)/4
=7.5m/s2
Answer:
There is no friction between the card and the cup.
Explanation:
A particle confined to move along a curved path has only one degree of freedom. inclined plane are some examples of constrained motion. Every condition of constraint reduces the number of degree of freedom by one.
I hope this helps!
Answer:
Inertia
Explanation:
Inertia is the property that any physical object has of remaining in its state of relative motion. Therefore, it is the resistance that opposes matter to modify its state of motion, which includes changes in speed or changes in the direction of movement.
Answer:
Decreases by
times
Explanation:
The intensity of a sound is defined as the energy of the sound that is flowing in an unit time through the unit area which is in the direction that is perpendicular to the direction of the sound waves movement.
The intensity of energy is described by the inverse square law. It states that the intensity varies inversely with the distance square of the distance.
In other words, the sound intensity decreases as inversely proportional to the squared of the distance. i.e. 
In the context when the distance was 3 m, the intensity of the sound was = 
But when the distance became 6 cm or 0.06 m, the sound intensity decreases by = 
=
times