The first question's answer is :
If, F=ma
Then, 15N= 2.1kg (a)
15/2.1=a
7.14=a
Therefore, acceleration = 7.14m/s^2
sorry I am not sure about the second question :-(
Answer:The greater the density of a medium, the slower the speed of sound. This observation is analogous to the fact that the frequency of a simple harmonic motion is inversely proportional to m, the mass of the oscillating object. The speed of sound in air is low, because air is easily compressible.
Explanation:
Answer:
When the bag of apples are on the floor, the force of gravity is equal to the force applied in the upward direction.
But when the girl picks up the bag of apples, she applies a force on the bag of apples in the upward direction greater than that of the gravitational force.
Explanation:
Gravitational force for an object is always constant at a specific point. When an object is in the state of rest, there is an equal force opposite to the direction of Gravitational Force.
Now, to lift an object upwards, an external force must be applied that is greater than the force of gravitation.
So, when the girl picks up the bag of apples,
Gravitational Force < Force applied by the girl to lift the bag.
If he runs at the same speed he will cover next 200m in 40s
that is at the average of 4.0m
