Answer:
C.The car appears to be moving 30 km/hr in the opposite direction of the bus.
Explanation:
There are two reference systems involved in this situation:
- Reference system S: this is the reference system where velocities are measured with respect to the ground. In this reference system, the car is parked, so its velocity is
- Reference system S': this is the reference system moving with the bus. This reference system is moving with a velocity of with respect to the reference system S
Calling the velocity of the car in the reference system S', we have:
From which
and the negative sign means that a passanger in the bus observes the car moving in the opposite direction.
Answer:
20 cm to the right of the center or 20+50 = 70 cm from the left side.
Explanation:
The length of meter stick is 1 m = 100 cm
Balance point on 50 cm
From the center the 20 N weight is 50-20 = 30 cm
Torque is obtained when force is multiplied with the distance
As the force is conserved we have
The distance will be 20 cm to the right of the center or 20+50 = 70 cm from the left side.
Answer:
197.5072.
Explanation:
According to the Coulomb's law, the magnitude of the electrostatic force of interaction between two charges and
which are separated by the distance
is given by
<em>where,</em> k is the Coulomb's constant.
For the case, when,
Then, using Coulomb's law,
For the case, when,
Then, using Coulomb's law, the new electric force between the charges is given by,