newton 1st law: w no external force, a body will stay at rest or in constant uniform motion.
a motor raises the car up the tower. cuz it moves w/ constant vel, there is no external force: the motor force is the same n in opposity direction as the gravity force on car.
<h2>
<u>KINETIC ENERGY</u></h2>
<h3>Problem:</h3>
» Kinetic energy of 35 J and a mass of 34 kg, how fast is the object moving?
<h3>Answer:</h3>
— — — — — — — — — —
<h3>Formula:</h3>
To calculate the velocity of a kinetic energy, we can use formula
where,
- v is the velocity in m/s
- KE is the kinetic energy in J (joules)
- m is the mass in kg
Based on the problem, the givens are:
- KE (Kinetic energy) = 35 J
- m (mass) = 34 kg
- v (velocity) = ? (unknown)
<h3>Solution:</h3>
To get the velocity, substitute the givens in the formula above then solve.
Therefore, the velocity is 1.435 m/s.
Answer:
c. The force on the charge at the origin is 0
Explanation:
We know by Coulomb's law:
Force between to two charges (here repulsive since both are +ve) sperated by distance 'r' in space is:
where:
= permittivity of free space
being the charges
In this case the product remains constant and also the distance "r" is constant which yields the force identical in each case.
Since identical charges are kept at all the four corners of a diamond shape and are equidistant from the origin where another charge of +5 μC is kept, all the charges from the vertices will apply equal repulsive force on the charge at origin cancelling out the force vectors which yields the force to be zero.