Answer: Light waves move faster than sound waves, which are longitudinal.
Light waves can also travel through space.
Sound waves, being longitudinal, are slower than light waves, and do not travel through space.
Find stress using the formula Stress = Force / Area. Here, force
exerted by 85kg person on stool is F = mg = 85kg * 9.8 m/s^2 = 833N. Find total
area of 3 legs A = 3 π (D/2)^2 = 3 π (2.5 x 10^-2 / 2)^2 = 1.4726 x 10^-3 m^2.
Now substitute in Stress = Force/Area. Stress = 833N / 1.4726 x 10^-3 m^2 =
5.656 x 10^5 N/m^2. Find strain using the formula strain = Stress / Young’s
modulus. For wood, Y = 1.3 x 10^10 N/m^2. Thus, strain = 5.656x10^5 N/m^2 /
1.3x10^10 N/m^2 = 4.35 x 10^-5 = 0.00435%.
Therefore, the legs decrease by 0.00435%
Answer:
a. 10.0 J
Explanation:
Given parameters:
Weight of bowling ball = 10N
Height of building = 5m
Distance of fall = 1m
Unknown:
Kinetic energy of the ball = ?
Solution:
Kinetic energy is the energy due to the motion of a body.
Mathematically;
K.E = mv²
Since this body is falling under gravity;
K.E = mgh
mg = weight of the ball
h is the height
Insert the parameters and solve;
K.E = 10 x 1
K.E = 10J