An electric hoist does 500 joules of work lifting a crate 2 meters. How

8. A car travels from Town A to Town B on one road at different speeds and stops at red lights. If you know the distance between

ryzh [129]

Answer:

The velocity

Explanation:

The difference between speed and velocity is the following:

- Speed is defined as the ratio between the total distance covered by an object and the time taken:

$speed = \frac{distance}{time}$

and it is a scalar.

In this problem, we cannot calculate the speed of the car, because we don't know exactly what is the distance covered by the car (we only know the distance between town A and town B, but we don't know if the car has travelled on a straight path or not, so we don't know the distance it has covered)

- Velocity is defined as the ratio between the displacement and the time taken:

$velocity=\frac{displacement}{time}$

(note that velocity is a vector)

Displacement is the shortest distance (straight line) between the final and the initial point of the motion: in this case, it corresponds to the distance between town A and town B, which we know. Since we also know the time of the trip, this means that we can calculate the velocity of the car.

4 0

3 years ago

A buoy is a floating device that can have many purposes, but often as a locator for ships. Collin constructs a hollow metal buoy

Yuri [45]

Answer:

A) since the density of the buoy is half the density of sea water when the buoy is at rest on an ocean half of the buoy will be submerged in water

B )angular frequency ( w ) = $\sqrt{\frac{3g}{h} }$

c ) h = 1.34 m ( 4 $\pi ^{2}$ / 3g )

Explanation:

A) since the density of the buoy is half the density of sea water when the buoy is at rest on an ocean half of the buoy will be submerged in water this is because the substances with lesser density floats when placed in a substance with a higher density

B ) when the Buoy is at rest ( t = 0 ) and is then pushed down calculate angular frequency ( w ) of small oscillations in terms of the given variables

volume of cone = hA /3.

h = height of cone, A = Base Area.

therefore the total volume of the Buoy above water level ( at rest )

= ( $\pi r^{2} * \frac{h}{3}$ ) * 2 = $\frac{\pi r^{2} h }{6}$