Answer: C
Explanation:
A bird flying in the air is 3D motion as the bird move up, down, right, left all the possible direction. A leaf falling from a tree is also a 3D motion because a leaf never fall in absolute vertical manner. A lady bug crawling on a soccer ball also 3D. If lady bug crawling on a plane like floor then it is 2D but now lady bug crawling on soccer ball which is in spherical shape so it is also 3D motion. Only train travelling along a track is 2D because train cannot move up and down and the track of train is in a plane. So it is 2D motion.
Answer: 0.4m
Explanation:
Given that:
Amplitude of wave = 2.0 m
Wavelength (λ)= ?
Frequency F = 500Hz
Speed V = 200 m/s
The wavelength is measured in metres, and represented by the symbol λ.
So, apply the formula:
Wavespeed V= Frequency F xwavelength λ
200m/s = 500Hz x λ
λ = 200m/s / 500Hz
λ = 0.4m
Thus, the wavelength is 0.4 metres
Answer:
280 N
Explanation:
Applying Newton's third second law of motion,
F = m(v-u)/t................... Equation 1
Where F = Magnitude of the average force on the ball during contact, v = final velocity of the ball, u = initial velocity of the ball, t = time of contact of the ball and the wall.
Note: Let the direction of the initial velocity of the ball be positive
Given: m = 4 kg, u = 3.0 m/s, v = -4.0 m/s (bounce off), t = 0.1 s
Substitute into equation 1
F = 4(-4-3)/0.1
F = 4(-7)/0.1
F = -28/0.1
F = -280 N.
Note: The negative sign tells that the force on the ball act in opposite direction to the initial motion of the ball
Answer:
3,150,000N
Explanation:
According to Newton's second law;
F = mass * acceleration
Given
Mass = 45000kg
acceleration = 70m/s^2
Substitute
F = 45000 * 70
F = 3,150,000N
Hence the force required to be produced by the rocket engines is 3,150,000N
