Answer:
Kinetic energy of the projectile at the vertex of the trajectory:
.
Work done when firing this projectile:
.
Explanation:
Since the drag on this projectile is negligible, the horizontal velocity
of this projectile would stay the same (at
) throughout the flight.
The vertical velocity
of this projectile would be
at the vertex (highest point) of its trajectory. (Otherwise, if
, this projectile would continue moving up and reach an even higher point. If
, the projectile would be moving downwards, meaning that its previous location was higher than the current one.)
Overall, the velocity of this projectile would be
when it is at the top of the trajectory. The kinetic energy
of this projectile (mass
) at the vertex of its trajectory would be:
.
Apply the Pythagorean Theorem to find the initial speed of this projectile:
.
Hence, the initial kinetic energy
of this projectile would be:
.
All that energy was from the work done in launching this projectile. Hence, the (useful) work done in launching this projectile would be
.
when velocity and time both are constant and when velocity will decrease the acceleration will be negative
Answer:
Explanation:
Given
length of wire 
change in length 
mass of wire 
Young's modulus for silver 
load on wire 

change in length is given by

Where A=area of cross-section




also wire is the shape of cylinder so cross-section is given by





Answer:
the force acting on the team mate is 1.19 kN.
Explanation:
given,
mass = 196 lbm
while tackling, the deceleration is from velocity 6.7 m/s to 0 m/s
time taken for deceleration = 0.5 sec
F = mass × acceleration
acceleration =
= -13.4 m/s²
1 lbs = 0.453 kg
196 lbs = 196 × 0.453 = 88.79 kg
F = 88.79 × 13.4
F = 1189.786 N = 1.19 kN
hence, the force acting on the team mate is 1.19 kN.
We're happy that you're asking for the "displacement", because displacement is simply the straight-line distance between the start-point and end-point, and we don't care about any of the motions or gyrations along the way.
From the graph:
-- The location of the object at time-zero, when time begins, is 10 meters.
-- The location of the object after 6.0 seconds is 4 meters.
-- The distance between the start-point and end-point is
(final location) - (initial location)
-- So Displacement = (4 meters) - (10 meters)
<em>Displacement = -6 meters</em>