Answer: A. Transverse
Explanation:
Sound is a mechanical transverse wave, it travels faster in solids than in liquids or gases. This is because the speed of the mechanical waves is determined by a relationship between the elastic properties of the medium in which they are propagated and the mass per unit volume of the medium.
In addition, the speed of sound varies with changes in the temperature of the medium. This is because an increase in temperature means that the frequency of interactions between the particles that transport the vibration increases, hence this increase in activity increases the speed.
Hence:
<h3>Sounds travels in a <u>transverse</u> wave</h3>
Answer: Option A: The number of trees sampled.
The accuracy can be understood as how close is the measured value to the true value. The aim is to monitor the population size of the insect pest in a 50 square kilometer. Random trees are selected, and number of eggs and larvae are counted. So, the measured value would be closer to actual value when the number of trees sampled are increased. More the number of trees sampled, less would be the chances of error and the accuracy of the estimate would increase.
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
