Answer:
22km/h
Explanation:
The speed of the keys relative to the ground will be given by the sum of speed of keys with respect to the ground and the speed of keys with respect to the skater
Given that the speed of keys with respect to the ground is 8 m/s while the speed of keys with respect to skater is 14 km/h then the relative speed which combines both speeds will be 8+14=22 km/hr
90 degrees - 30 = 60 degrees
Velocity = (5m/s - 4.35m/s x cos(30)) / cos(60)
Velocity = 2.47 m/s
The answer is D) 2.47 m/s at 61.9 degrees
Answer: When the fluid cools, the kinetic energy of the molecules decreases. this causes the molecules to slow down and move closer together, the density of the fluid increases and the fluid sinks
Explanation: Just took the test & it gave the answer or sample response.
If you double the velocity of an object, its momentum doubles. but for the same increase in velocity, the kinetic energy increases 4 times..
Answer : The velocity of an electron is, 
Explanation :
According to de-Broglie, the expression for wavelength is,

and,

where,
p = momentum, m = mass, v = velocity
So, the formula will be:
.............(1)
where,
h = Planck's constant = 
= wavelength = 
m = mass of electron = 
v = velocity of electron = ?
Now put all the given values in formula 1, we get:


Thus, the velocity of an electron is, 