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.
A conservative force is a force that when work is done against this force the work done does not depend on the path taken only the initial and final position.
The answer would be a frog!
Because fossil fuels are non-renewable resources.
This means, if we run out, we will not be able to reproduce it.
It would be the last that exists. (For oil, it'd be for the next few hundred years.)
Answer:
The force acting in x direction is 34.44 N
Explanation:
We have,
Force acting on the box is 65 N at an angle of 58 degrees to the horizontal the surface of frictional.
It is required to find the net force in x- direction.
The net force acting in the x- direction is given by :

So, the force acting in x direction is 34.44 N.