Answer:
The new speed of the ball is 176.43 m/s
Explanation:
Given;
mass of the ball, m = 7 kg
initial speed of the ball, u = 5 m/s
applied force, F = 300 N
time of force action on the ball, t = 4 s
Apply Newton's second law of motion;

where;
v is new speed of the ball

Therefore, the new speed of the ball is 176.43 m/s
One should check the battery every week.
A battery if not maintained properly can cause it to die earlier or get damaged. The reasons why should the battery be checked regularly is that due to improper management of the battery and also the weather conditions, the battery usually gets corroded easily and the battery won't be able to work properly.
The connections must be checked properly so that the battery gets charged properly and should not die while driving.
The answer is A. Newton's third law of motion states that for every action, there is an equal and opposite reaction. A rocket exerts a large force on the gas that is in the rocket chamber (action). The gas thus exerts a large reaction force forward on the rocket (reaction). The large reaction force is called thrust.
Answer:
a. The human body has nearly the same density as salt water after exhaling.
b. The human body will always float in the Dead Sea.
Explanation:
According to the concept of floating on the basis of density, any body that is put in a fluid of density greater than its own density will always float due to the force of buoyancy from the liquid.
- The portion of the object submerged while the object is floating depends upon the density of the object as compared to the density of the fluid. This is governed by the equation:

where:
density of the fluid
density of the object
volume of the object submerged in the fluid
total volume of the object
Any object that is given any initial velocity and which follows a path due to gravitational force acting on it and by the frictional resistance of the atmosphere is called a projectile. This is because the object is projected and not influenced by anything except gravity.