Answer:
Be pushed away from each other.
Explanation:
An object that's moving doesn't necessarily change its speed or acceleration. Also, the force applied to it doesn't need to change ... in fact, a moving object doesn't need ANY force applied to it in order to keep moving.
But any moving object WILL have a change in its position ... THAT's how you know it's moving, and that's WHY you say "It's moving !". (choice-B)
Answer:
The velocity of the freight car decreases.
Explanation:
This question is answered by the conservation of momentum principle.
When the freight car is moving at a certain speed, it has a constant momentum.
We will call this M1.
The equation for M1 will be:
M1 = Mass * Speed
Now when the coal is dumped into the freight car, the Mass increases.
Since conservation of momentum states that the momentum will remain the same. We have:
M1 = (Mass of freight + Mass of coal) * Speed
Since M1 is constant, if the mass increases, the speed had to decrease to keep the equation true.
Answer:
4.4 seconds
Explanation:
Given:
a = -5.5 m/s²
v₀ = 0 m/s
y₀ = 53 m
y = 0 m
Find: t
y = y₀ + v₀ t + ½ at²
0 = 53 + 0 + ½ (-5.5) t²
0 = 53 − 2.75 t²
t = 4.39
Rounded to two significant figures, it takes 4.4 seconds for the object to land.
Answer:
The focal length is 16.86 cm and the distance of the man if he wants to form an upright image of his chin that is twice the chin's actual size is 8.43 cm.
Explanation:
Given that,
Object distance u=1.54 m =154 cm
Image distance v = 15.2 cm
Magnification = 2
We need to calculate the focal length
Using formula of mirror
Put the value into the formula
We need to calculate the focal length
Using formula of magnification
Put the value into the formula
Using formula of for focal length
Hence, The focal length is 16.86 cm and the distance of the man if he wants to form an upright image of his chin that is twice the chin's actual size is 8.43 cm.
