Answer:
-26 m/s.
Explanation:
Hello,
In this case, since the vertical initial velocity is 26 m/s and the vertical final velocity is 0 m/s at P, we compute the time to reach P:

With which we compute the maximum height:

Therefore, the final velocity until the floor, assuming P as the starting point (Voy=0m/s), turns out:

Which is clearly negative since it the projectile is moving downwards the starting point.
Regards.
The train is moving at 50 m/s and Emma is walking down the aisle with 1 m/s speed in the same direction of train. The relative velocity of Emma with respect to other passengers pf the train would be 1 m/s. This is because, the train is not moving relative to them and only emma is moving at 1 m/s. If a person observes from outside, Emma would have (50 +1) m/s = 51 m/s velocity.
relative velocity when two objects are moving in same direction as oberved from outside observer:

relative velocity when two objects are moving in the opposite directionas oberved from outside observer:

Ok, now what do you want to know about it?
Answer:
a) 855.41J
b) 855.41J
Explanation:
The force equation is
N - mg - F sinθ = 0
N = mg + F sinθ
The frictonal force is =


substitute the value of the normal force in the above equation


= 151.96N
a) work done = F × d
= (151.96) × (6.5) cos30°
= 855.41 J
b) The increase in thermal energy of the block floor system will be equal to the work done by the worker
work done = F × d
= (151.96) × (6.5) cos30°
= 855.41 J