A crate is being pushed at a constant speed across the floor. The gravitational force on the crate is 80N, and the applied force is 50N. What are the other force(s) acting on the crate?

Friction force.

Explanation:

Force is defined as a pull or push acting on an object that changes the speed or direction of the motion.

When a crate is is being pushed at a constant speed across the floor along with gravitational force and the applied force, there will be a force of friction applied by the floor on the opposite direction of applied force.

Friction always opposes the applied force and resist the changes in the motion of the object.

Hence, the correct option is Friction force.

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.