A projectile motion is characterized by motion moving in a direction of an arc. It is acted upon by two component vectors: the horizontal and vertical. These two vectors are independent of each other when it comes to time of flight. The horizontal direction travels at constant speed, while the vertical direction travels at constant acceleration due to gravity, The time for an object to reach the ground would be equal, whether dropped from the sampe point or thrown in a projectile motion. Of course, this is assuming ideality wherein there is no air resistance.
So, the hang up time, or the time the object stayed on air is calculated using this equation:
a = Δv/t
Δv is the change in velocity which is the initial velocity when it was dropped to when it reaches zero velocity when it hits the ground.
9.81 m/s² = |(0 - 7.3)|/t
t = 0.744 seconds
Answer:
La velocidad es una magnitud física que expresa la relación entre el espacio recorrido por un objeto, el tiempo empleado para ello y su dirección. ... Su unidad en el Sistema Internacional de Unidades es el metro por segundo (m/s), e incluye la dirección del desplazamiento
Explanation:
Formulae for Kinetic energy is:
Kinetic Energy= 1/2xmassx(velocity)^2
For comparison we need to have same units,thus we convert 10g into Kg.
10g/1000=0.01Kg
Input the value of bullet in the formulae;
Kinetic Energy= 1/2x0.01kgx(400)^2
K.E=800J
Input value of the ball:
Kinetic Energy=1/2x80kgx(6.5)^2
K.E=1690J
Which means that th Energy of the ball is more than the bullet.
Answer: A. Work is done on the system and heat is transferred from the system for a net decrease in internal energy.
Explanation:
A refrigerator is a device which dispenses heat from the close system to a warmer area or in the surrounding. By dispensing the heat the internal temperature of the refrigerator drops. The system of refrigerator violates the second law of thermodynamics. As it performs the work to cool the region instead of heating the region. The work is done on the system and the internal energy decreases and the heat energy is liberated to the surrounding area. A refrigerator is an open system.
-- The table tennis ball bounces back with virtually its entire original speed.
-- The bowling ball rolls forward, so slowly that only complex expensive laboratory equipment can detect and measure its speed.
-- Once again, momentum is conserved !
