Answer:
W = 71J
Explanation:
Given force F = (5i+5j−1k)N
d = Δr
r1 = (−5,−3,−4)m
r2 = (2,5,0)m
Δr = r2 – r1 = (2-(-5), 5-(-3), 0-(-4))
Δr = (2+5, 5+3, 0+4) = (7i+ 8j +4k)m
W = F•d = (5i+5j−1k)•(7i+ 8j +4k)
W = 5×7 + 5×8 +-1×4 = 35 + 40 - 4
W = 71J
The scalar operates only on the magnitude of the vector.
So the length of the vector may change ... becoming longer
or shorter ... but its direction doesn't change.
Answer:
(2)


Explanation:
<u>a)Kinematics equation for the first ball:</u>


initial position is the building height
The ball reaches the ground, y=0, at t=t1:

(1)
Kinematics equation for the second ball:


initial position is the building height
the ball is dropped
The ball reaches the ground, y=0, at t=t2:

(2)
the second ball is dropped a time of 1.03s later than the first ball:
t2=t1-1.03 (3)
We solve the equations (1) (2) (3):






vo=8.9m/s

t2=t1-1.03 (3)
t2=3.29sg
(2)
b)
t1 must : t1>1.03 and t1>0
limit case: t1>1.03:





limit case: t1>0:




Answer:
check the screen shot please
Answer: Light could be thought of as a stream of tiny particles discharged by luminous objects that travel in straight paths.
Explanation:
We can define "radiation" as the transmision of energy trough waves or particles.
Particularly, light is a form of electromagnetic radiation, so the "tiny particles" of light are discharged by a radiating object, particularly we can be more explicit and call it a luminous object, in this way we are being specific about the nature of the radiation of the object.