Answer:
Option D
Explanation:
The work done can be given by the mechanical energy used to do work, i.e., Kinetic energy and potential energy provided to do the work.
In all the cases, except option D, the energy provided to do the useful work is not zero and hence work done is not zero.
In option D, the box is being pulled with constant velocity, making the acceleration zero and thus Kinetic energy of the system is zero. Hence work done in this case is zero.
Answer: A compound is a substance formed when two or more elements are chemically joined. Water, salt, and sugar are examples of compounds. When the elements are joined, the atoms lose their individual properties and have different properties from the elements they are composed of.
Answer:
134r kgm^-1 or 1344 kg /m
Explanation:
Momentum is is given by:
p=mv
Where:
p is momentum, m is mass in kg and v is velocity in ms−1
p=120kg×11.2 m/ s= 1344 kgms=1344kgm^−1
Each person is 80kg. 320/4
