1. ## Writing expression

1. It is estimated that the Earth is losing 4000 species of plants and animals every year. If S represents the number of species living last year, how many species are on Earth this year?

2. The kinetic energy of a particle of mass m is found by taking one-half of the product of the mass (m) and the square of the velocity (v). Write an expression for the kinetic energy of a particle.

2. Originally Posted by Patience
1. It is estimated that the Earth is losing 4000 species of plants and animals every year. If S represents the number of species living last year, how many species are on Earth this year?
If you have S species one year and lose 4000 species each year then you have S - 4000 species in the following year.

Originally Posted by Patience
2. The kinetic energy of a particle of mass m is found by taking one-half of the product of the mass (m) and the square of the velocity (v). Write an expression for the kinetic energy of a particle.
K = (1/2)mv^2
where K is the kinetic energy and v^2 is v times v.

-Dan