Respuesta :
Question:
A ball has a 17 J of kinetic energy and lB mechanical energy is 25 Joule
a. Find the gravitational potential energy of the ball.
b. if the ball has a mass of 3.2 kg, what is its height above the ground?
c. What is the speed of the ball?
Answer:
a. = 85
b. h = 0.25 m
c. = 3.26 m/s
Explanation:
Part A
PEgrav = m ו g • h
In the above equation, m represents the mass of the object, h represents the height of the object and g represents the gravitational field strength (9.8 N/kg on Earth) - sometimes referred to as the acceleration of gravity. So, to find:
GPE = ME - KE = 25 - 17 = 85
Part B
The formula simplifies to: h max = h + V₀² / (2 × g) and the time of flight is the longest.
The vertical velocity is equal to 0 (Vy = 0), and that's the case of horizontal projectile motion.
The equation may be written as:
GPE = mgh
8 = 3.2 × 10 × h
h = 0.25 m
Part C
The ball speed is calculated by dividing the distance by the time. If the time was 3 seconds, the average speed will be 60/3 = 20 feet per second (6.1 m/sec). KE = 1/2 MV²
17 = 1/2 × 3.2 x V²
V = 17 ÷ 1.6
Note, this is only the average ball speed, the speed of the ball at the time of release would be greater.
