Answer:
Speed of the ball relative to the boys: 25 km/h
Speed of the ball relative to a stationary observer: 35 km/h
Explanation:
The RV is travelling at a velocity of
Here we have taken the direction of motion of the RV as positive direction.
The boy sitting near the driver throws the ball back with speed of 25 km/h, so the velocity of the ball in the reference frame of the RV is
with negative sign since it is travelling in the opposite direction relative to the RV. Therefore, this is the velocity measured by every observer in the reference frame of the RV: so the speed measured by the boys is
v = 25 km/h
Instead, a stationary observer outside the RV measures a velocity of the ball given by the algebraic sum of the two velocities:
v = +60 km/h + (-25 km/h) = +35 km/h
So, he/she measures a speed of 35 km/h.
Answer:
Metals, nonmetals and metalloids.
Explanation:
Vibrational energy, which as we know, causes heat!
The answer is 1/4
this is actually a very simple question because if you divide 3,600 by 4 that equals 900 so if you want them to be the same waight you need 3,600 to be multiplied by 1/4.
The correct answer to this question is C. nutcracker. A lever is the type of machine that has a fulcrum. So out of all the choices, a nutcracker is most likely the answer. Another example of a lever includes scissors. Thank you for posting your question. I hope that this answer helped you. Let me know if you need more help.