To solve this problem we will apply the concepts of acceleration according to the laws of kinetics. Acceleration can be defined as the change in velocity per unit time, that is,

Here,
v = Final velocity
u = Initial velocity
t = Time
Rearranging to find the initial velocity,

Now the acceleration is equal to the gravity, then,



The velocity of the shell at 5.5s after the launch is,




Therefore the magnitude of the velocity of the shell at 5.5s is -19.26m/s
Answer:

Explanation:
Potential difference between two points in constant electric field is given by the formula

here we know that

also we know that

now we have

now change in potential energy is given as



In this scenario, only conservative force is acting on the ice-cream hence energy is conserved.
Now, you know that ice-cream was held at a height of 1.75 m from ground. Taking ground( h= 0 meters) as reference,
Total energy of ice-cream before it fell = Total energy after it reached the ground.
Once ice-cream falls, all its GPE is converted into kinetic energy. Kinetic energy will be maximum just before it hits the ground. And since ice-cream is inelastic substance, it will come to at rest. That is, its GPE will be zero on the ground
Answer:
It is example of Closed system
Answer:
The net gravitational force on the mass is 
Explanation:
We have by Newton's law of gravity the force of attraction between masses 

Applying vales we get
Force of attraction between 135 kg mass and 38 kg mass is

Force of attraction between 435 kg mass and 38 kg mass is

Thus the net force on mass 38.0 kg is 