Answer:
Work is the energy required to move an object from one point to another. while power is the energy transferred per unit time.
Energy can also be defined as the ability to do work.
Answer:
W = -2080 J
Explanation:
initial position vector of the object is given as
similarly final position vector is given as
now the displacement of the object is given as
now we will have
now the force on the object is given as
so here in order to find the work done
Answer: 317.0 m/s
Explanation:
The motion of the bullet is a projectile motion, with:
- a uniform motion with constant speed v along the horizontal direction
- an accelerated motion with constant acceleration toward the ground
We know that the starting height of the bullet is h=1.4 m. If we consider the vertical motion only, the initial velocity is zero, so we can write:
The bullet reach the ground when y(t)=0, so the time taken is
During this time, the bullet travels d=168 m horizontally, so its horizontal speed (which is equal to the initial speed of the bullet) is given by
Since we know Mary's speed AND direction, we have
all the information we need to state her velocity.