A physical problem, urgent! Physics Questions! Hurry, hurry!

Problem: Object A moves in the same direction at a speed of x meters per second, and car B moves at a speed of 80 kilometers per hour, and the person sits in car B and stands still relative to car B.

Answer: If a person sees a object moving in the direction of ab's motion, then the actual velocity of a is .

80 meters per second.

If a person sees a object moving in the opposite direction to the direction of motion of ab, then the actual velocity of a is .

80 meters per second.

This contradicts the AB co-directional movement.

Therefore, the actual velocity of an object is meters per second.

Your first line, "car b", shouldn't have the word "medium" after it?

The answer to this question is kilometers per hour.

Solution: For the problem of relative motion, there are generally two directions to choose from. The title states that AB moves in the same direction, which shows that in the case of these two directions, A moves in the same direction as B at a speed of 24 meters per second faster than B; A moves in the same direction as A at a slower speed than B, and the difference in velocity is 24 meters per second.

After unit conversion.

24 m/s × 3600 s/hour × km/m = km/hour

Since A's speed is only 80 km hour, if B is slower than A, it won't be in the same direction as A, so this is not the case.

In another case, the velocity of B is 80 km hour + km hour = km hour

Untie; 24m s=km/h and because the two velocities are positive, the speed of a is greater than the speed of b.

Take b as a reference to b = 80 kmh so speed = km/h.

So a thing is measured in kilometers per hour.

That is, relative B moves at a speed of 24 meters per second, and the speed of B is added or subtracted by 24 meters per second, which is the actual speed of A.

If the pendulum can be seen as a single pendulum, then the periodic formula of the pendulum is t=2 (l g) g is the acceleration due to gravity =

The one-point key locust clock oscillates 50 times, 40 times Dan hits, 30 times and 20 times. That is, the late friend period of the weekly manuscript is 60, 50, 60, 40, 60, 30, 60, 20 seconds.

Respectively is, 2sand 3s

t=2π√（l/g) l=t^2g/4 π^2 ,,2s.and 3sSubstitution calculations.

The corresponding pendulum length l is , 1m,

The moon admirer looks down and sees the moon in the water at a distance of 5 square kilometers from the surface of the water, because the surface of the water is quite flat mirror, and the distance between the object and the image is equal to the plane mirror.

of 5 power kilometers, independent of water depth.

If the ring is intact, then the combined field strength at the center is zero.

It can be seen that after removing the d part, the combined field strength of the remaining part is equal to the field strength generated by the d part, and the direction is opposite.

Take d to study: e=k(q 2 r)d r 2=kqd 2 r 3, so the field strength generated by the remaining part of the ring is kqd 2 r 3, and the direction is pointed from the center of the circle to d

DM1 and M2 are both in free fall, and the initial velocity and acceleration are the same, so the distance passed by any change sock during the fall of the next is the same, so the distance between them (spring length) is also unchanged.

It is clear that the story of Galileo's overthrow of Aristotle and the discovery of the free-fall nuclear brotherhood is very clear.