Unlike velocity, speed is scalar, which means it is described by__only.
a. direction
b. magnitude
c. time
d. motion

- Magnitude only

Unlike velocity, speed is scalar, which means it is described by magnitude only.

The correct answer is magnitude.

Explanation: A scalar quantity is a quantity that has magnitude only. For example distance, speed etc.

A vector quantity is a quantity that has magnitude as well as direction. For example displacement, velocity etc.

Velocity is a vector quantity and speed is a scalar quantity.

Suppose, a car is moving with 3 meter per second. It represents the speed at which the car is moving.

But car is moving with 3 meter per second in south direction. It represents the velocity because 3 meter per second is magnitude and south is a direction.

Therefore, Unlike velocity, speed is scalar, which means it is described by magnitude only.

answer: the potential energy decreases from 379 j to 243 j

explanation:

for the law of conservation of energy, the total energy in a system must be conserved. the total energy of the system is given by the sum of kinetic (k) and potential (u) energy:

e = k + u

the total energy is e=675 j, and this does not change.

initially, the kinetic energy is k=296 j, so the potential energy is

at the end, the kinetic energy is k=432 j, so the potential energy is

so, we see that the potential energy has decreased from 379 j to 243 j.