Answer:
C. At the instant the ball reaches its highest point.
Explanation:
When a body is thrown up, it tends to come down due to the influence of gravitational force acting on the body. The body will be momentarily at rest at its maximum point before falling. At this maximum point, the velocity of the body is zero and since force acting on a body is product of the mass and its acceleration, the force acting on the body at that point will be "zero"
Remember, F = ma = m(v/t)
Since v = 0 at maximum height
F = m(0/t)
F = 0N
This shows that the force acting on the body is zero at the maximum height.
Answer:
2.49 * 10^(-4) m
Explanation:
Parameters given:
Frequency, f = 4.257 MHz = 4.257 * 10^6 Hz
Speed of sound in the body, v = 1.06 km/ = 1060 m/s
The speed of a wave is given as the product of its wavelength and frequency:
v = λf
Where λ = wavelength
This implies that:
λ = v/f
λ = (1060) / (4.257 * 10^6)
λ = 2.49 * 10^(-4) m
The wavelength of the sound in the body is 2.49 * 10^(-4) m.
Energy resources that cannot be replaced are called "non-renewable" energy resources.
Mechanical waves transfer energy by inducing vibrations in the propagation medium.
