<span>b. objects.
</span>..............
Let us examine the given situations one at a time.
Case a. A 200-pound barbell is held over your head.
The barbell is in static equilibrium because it is not moving.
Answer: STATIC EQUILIBRIUM
Case b. A girder is being lifted at a constant speed by a crane.
The girder is moving, but not accelerating. It is in dynamic equilibrium.
Answer: DYNAMIC EQUILIBRIUM
Case c: A jet plane has reached its cruising speed at an altitude.
The plane is moving at cruising speed, but not accelerating. It is in dynamic equilibrium.
Answer: DYNAMIC EQUILIBRIUM
Case d: A box in the back of a truck doesn't slide as the truck stops.
The box does not slide because the frictional force between the box and the floor of the truck balances out the inertial force. The box is in static equilibrium.
Answer: STATIC EQUILIBRIUM
Answer:
<h3>25km/hr</h3>
Explanation:
Velocity is the change in displacement of a body with respect to time.
Velocity - Displacement/time
Given
displacement = 76km
Time = 3hours
Substitute the given parameters into the formula;
Velocity = 75km/3hrs
Velocity = 25km/hr
Hence the velocity of the narwhal is 25km/hr
The <em>mass</em> of an object is a measure of how much stuff it's made of. So it's
a property of the object, like the object's length or color. It doesn't depend on
where the object is located right now, or on what else is around it..
The <em>weight</em> of an object is the measure of the gravitational force between it
and something else. The strength of the force depends on the size of both
masses, and also on how far apart they are. So the weight does depend on
where the object is located right now, and on what else is around it.
I think that sums it up fairly well.
Answer:
According to Einstein's famous equation, matter can convert into energy (and viceversa) as follows:
where
E is the energy
m is the mass
c is the speed of light (
)
Given the huge value of 
, we see that even a tiny amount of matter is able to release a huge amount of energy, when the whole mass is converted into energy. This is precisely what happens in nuclear reactions. For example, in the process of nuclear fusion (that occurs in the core of the stars), two light nuclei fuse together into a heavier nucleus. The mass of the final nucleus is lower than the total mass of the initial nuclei, so part of the mass has been converted into energy according to the equation above: this is why the amount of energy produced by stars is so big.
