Answer:
the normal force that the wall exerts on the ball
Explanation:
As Newton's third law states:
"when an object A exerts a force on object B, then object B exerts an equal and opposite force on object A".
If we apply this law to this problem, we can identify the ball as object A, and the wall as object B. As the ball hits the wall, the ball exerts a force on the wall (toward the direction of motion of the ball), so the wall exerts an equal and opposite force on the ball (in the opposite direction). This force is the normal force of the wall, and it is responsible for pushing the ball back towards Erica.
Answer:
Explanation:
mass of elephant, m1 = 5240 kg
mass of ball, m2 = 0.150 kg
initial velocity of elephant, u1 = - 4.55 m/s
initial velocity of ball, u2 = 7.81 m/s
Let the final velocity of ball is v2.
Use the formula of collision


v2 = - 16.9 m/s
The negative sign shows that the ball bounces back towards you.
(b) It is clear that the velocity of ball increases and hence the kinetic energy of the ball increases. This gain in energy is due to the energy from elephant.
Explanation:
Loudness of sound is a measure of response of sound to our ear. Loudness of sound is not simply the energy reaching the human ear, but it also tells about the sensitivity of human ear detecting this energy. Loudness of sound is measured in decibel (dB). As energy reaching the ear depends on square of amplitude, loudness of sound depends on various factors namely,
(i) Amplitude of sound waves
(ii) Sensitivity of ear
(iii) Distance from the source of the sound and the listener.
Atomic disguise makes helium look like hydrogen. ... A helium atom consists of a nucleus containing two positively charged protons and two neutrons, encircled by two orbiting electrons which carry a negative charge. A hydrogen atom has just one proton and one electron