As we know that total work done by a force is given by
so it is product of force and displacement along same direction
as we can write it as
so it must be the product of force and displacement in same directions so correct answer must be
<u>B. in the same direction as the displacement vector and the motion.</u>
Answer:
1.08 m/s
Explanation:
This can be solved with two steps, first we need to find the time taken to fall 9.5 m, then we can divide the horizontal distance covered with time taken to calculate the velocity.
Time taken to fall 9.5 m
vertical acceleration = a = 9.8 m/s^2.
vertical velocity = 0, (since there is only horizontal component for velocity, )
distance traveled s = 9.5 m.
Substituting these values in the equation
⇒ t= 1.392 sec
Velocity needed
We know the time taken (1.392 s) to travel 1.5 m,
So velocity = 1.5 m / 1.392 s = 1.08 m/s
hence velocity of the diver must be at least 1.08 m/s
Answer:
Explanation:
*Edit: The original question states a mass of . Since the, the poster has corrected it to
and therefore the answers have been change to account for the typo.
The impulse-momentum theorem states that the impulse on a object is equal to the change in momentum of the object.
Therefore, we have the following equation:
, where
is impulse (another way to find impulse) and
is change in momentum.
Because the car is being slowed to a rest, its final velocity will be zero, and therefore its final momentum will also be zero. Since momentum is given as , the car's change in momentum is
.
As we wrote earlier, this is also equal to the magnitude of impulse on the object. The time it takes to stop the car is actually irrelevant to finding the total impulse. However, if we were to calculated the average applied force on the car, we would need how long it takes to bring it to rest (refer to ).
The direction of the impulse must be exactly opposite to the car's direction, since we are slowing it to a stop.
Therefore, the impulse on the car is .