Objects with equal speeds definitely have equal velocities. -- FALSE. For equal velocities, they also have to be going in the same direction.
If you are given an object's velocity, you can definitely determine its speed. -- TRUE. If you know the velocity, then you know both the object's speed and its direction.
If you know the distance an object travels, and the time it takes to do so, you can determine the object's velocity. -- FALSE. Knowing the distance and time, you can figure out the object's speed. But if you don't also know the direction it's moving, then you can't say what its velocity is.
If an object moves at constant speed, it must also be moving at constant velocity. -- FALSE. Besides constant speed, it also needs to move in a straight line to have constant velocity. If it turns, its velocity changes, even if its speed doesn't.
If an object moves at constant velocity, it must also be moving at constant speed. -- TRUE. Constant velocity means its speed AND its direction are not changing.
Objects with equal velocities definitely have equal speeds. -- TRUE. If their velocities are equal, then their speeds are equal AND they're moving in the same direction.
After laboring through this one, I'm wondering if there can possibly be any more ways to say the same thing.
<span>The true brightness of an object
is called its luminosity. It is the total amount of energy emitted by bright or
meteorological objects over a period of time. It has the SI unit of joules per
second or watts. So the answer is letter A. Intensity is the measure of how
strong the substance or object is when it projects something. Magnitude is a
measure of how great is the size the object produces. Viscosity is the measure
of flow of a substance.</span>
1. Answer: A skydiver whose air resistance is equal to that of her weight.
A skydiver free falls under gravity but her rate of fall slows down due to drag -air resistance. when this air resistance becomes equal to her weight, the two get balanced and the body does not accelerate or decelerates.
2. Answer: Gravity
Contact forces are those which act when there is physical contact between two bodies. For example: normal force, tension and spring force.
Non-contact forces act between two bodies even when they are at a distance apart. For example: gravity, electric force, magnetic force etc.
3. Answer: The tendency of an object's motion to remain the same.
Inertia is a property of matter by virtue of which it tends to remain in its state of motion or rest. It does depend on mass of the object, more the mass, more is inertia. For example, cycle can be easily moved but we need real push hard for a car to move.
4. Answer: 254 N
The man pushes the box with 310 N force at an angle of 55 degrees to the horizontal.
we can write this in terms of horizontal (
)and vertical component (
).
Horizontal component: 
Vertical component: 
The vertical component would act towards the floor making the job more difficult to move the job.
To determine what the cyclists average speed is, simply divide the distance the cyclist has travelled by the time the cyclist has traveled for.
Assuming that this is the average rate the cyclist is moving at it would be 12 km/hr.
Answer:
Basic kinematics, negating drag and assuming ideal conditions, we use the equation:
d=vi*t+1/2*a*t^2
Since vi is 0 (we know this because you’re dropping it, not throwing it)…
…and the only acceleration acting on it is gravity, a=9.8 m/s^2…
…we get
d=1/2(9.8)(5)^2
Explanation:
Some quick mental math tells us that this is about 125 m.
Plugging it in, we find it to be 122.5 m.
