Answer:
physical cosmology, the Big Rip is a hypothetical cosmological model concerning the ultimate fate of the universe, in which the matter of the universe, from stars and galaxies to atoms and subatomic particles, and even spacetime itself, is progressively torn apart by the expansion of the universe at a certain time
Answer:
Explanation:
I assume you are asking for the acceleration of the ball, not the velocity (in fact, the velocity is already given).
The acceleration is:
where in this case we have:
v = 24 m/s is the final velocity
u = 0 is the initial velocity
t = 8 s is the time interval for the velocity to change
Solving the equation,
Potential energy can be calculated using the following rule:
potential energy = mgh where:
m is the mass = 85 kg
g is the acceleration due to gravity = 9.8 m/sec^2
h is the height = 4 km = 4000 meters
Substitute in the above equation to get the potential energy as follows:
Potential energy = 85*9.8*4000 = 3332000 joules
Answer: The force of reaction force of the ground accelerates the car on a level road.
Explanation:
When the wheels apply tractive force on the wheels by applying torque that is generated by engine of the car, the wheels in contact with the road tend to move backwards at the point of contact thus exerting a force in the direction opposite to the motion of the car. Now according to Newton's third law an equal and opposite forces act on the car which tend to accelerate the car in the direction of motion.