The total mechanical energy of the ball is the sum of its potential energy U and its kinetic energy K, therefore:

so, the total mechanical energy of the basketball is 118 J.
The power of the engine is 320 W.
<u>Explanation:</u>
Power may be defined as the rate of doing work (or) work done per unit time. One unit of energy is used to do the one unit of work.
Power = Work done / Time taken
Given, Force = 80 N, height = 5 m , final velocity = 4 m/s
To calculate the power, we must know the time taken.
To find the time, use the distance and speed formula which is given by
Time = Distance / speed
Here distance = 5 m and speed = 4 m/s
Time = 5 / 4 = 1.25 s.
Now, Power = work done / time
= (F * d) / t = (80 * 5) / 1.25
Power = 320 W.
The standard unit of power is watt (W) which is joule per second.
Answer: 20.21 kg
Explanation:
The mass hanging from the pulley is pulling the cart. The force by which cart is being pulled is equal to weight of the hanging mass.

⇒F=0.200 kg ×9.8 m/s²=1.96 N
Since there is no other force acting on the cart and there is no friction, so this force will pull the cart.
The Cart covers 1.12 m distance in 4.8 s.
From the equation of motion,
s = u t + 0.5 × a t²
We will find the acceleration of the cart,
Distance covered, s = 1.12 m
Initial velocity, u = 0 ( staring from rest)
Time taken, t = 4.8 s
⇒1.12 m = 0 + 0.5 × a × (4.8 s)²
⇒a = 0.097 m/s²
Now the force which causes this acceleration is:
F = ma
where m is the mass of the cart and a is the acceleration of the cart
⇒1.96 N = m×0.097 m/s²
⇒m = 20.21 kg
Hence, the mass of the cart is 20.21 kg.
Answer:
The dentist uses X-ray radiography, which takes too short a time to cause those problems.
Explanation:
I took the test on Edg