Answer: 2.22s
Explanation: wave speed = 450 m/s, A = amplitude = 1.6mm, λ= wavelength = 0.19m
Wave speed = distance traveled / time taken
Distance traveled = 1km = 1000 m
450 = 1000/ t
t = 1000/ 450 = 2.22s
Answer:
b. B
Explanation:
Picture B has the smallest peaks among all which henceforth makes the wavelength i.e. distance between two adjacent crests or troughs, small.
Answer:
F = 263.51 N
Explanation:
given,
diameter of wheel = 78 cm
diameter of axle = 14.8 cm
Force exerted on the rim of wheel = 150 N
Force applied outside the axle = ?
To prevent rotation wheel from rotating the Force 'F' should be applied outside of the axle.
Net momentum about the center of mass should be zero
now,
Moment of about center due to 150 N = moment about center due to F on axle
7.4 F = 1950
F = 263.51 N
Hence, Force exerted outside of the axle in order to prevent the wheel from rotating is equal to 263.51 N.
The phase change (from gas to liquid) that the steam undergoes right when it touches your skin releases a lot of energy right onto your skin so it burns a ton. The boiling water would just burn you until it reaches the same temperature as your skin.
A mass suspended from a spring is oscillating up and down, (as stated but not indicated).
A). At some point during the oscillation the mass has zero velocity but its acceleration is non-zero (can be either positive or negative). <em>Yes. </em> This statement is true at the top and bottom ends of the motion.
B). At some point during the oscillation the mass has zero velocity and zero acceleration. No. If the mass is bouncing, this is never true. It only happens if the mass is hanging motionless on the spring.
C). At some point during the oscillation the mass has non-zero velocity (can be either positive or negative) but has zero acceleration. <em>Yes.</em> This is true as the bouncing mass passes through the "zero point" ... the point where the upward force of the stretched spring is equal to the weight of the mass. At that instant, the vertical forces on the mass are balanced, and the net vertical force is zero ... so there's no acceleration at that instant, because (as Newton informed us), A = F/m .
D). At all points during the oscillation the mass has non-zero velocity and has nonzero acceleration (either can be positive or negative). No. This can only happen if the mass is hanging lifeless from the spring. If it's bouncing, then It has zero velocity at the top and bottom extremes ... where acceleration is maximum ... and maximum velocity at the center of the swing ... where acceleration is zero.
