Which of the following is not a type of system?

Biomedical

Ecological

Social

Biological

(not sure if this is physics but it doesn't give me the option to pick science for subject)

A 0.59 kg bullfrog is sitting at rest on a level log. how large is the normal force of the log on the bullfrog?

What are three ways to speed up a reaction?

Two small plastic spheres between them has magnitude 0.22 N. What is the charge on each sphere is one the other? Explain whether it can be determined from the information give, whether the charges are positive or negative.

A laser beam is incident from the air at an angle of 30.0° to the vertical onto a solution of Karo syrup in water. If the beam is refracted to 19.24° to the vertical, what is the index of refraction of the syrup solution?

If 270 million people in the United States jumped up in the air simultaneously, pushing off earth with the average force of 800 N each time of 0.10 seconds, what would happen to the 5.98*10^24 kg earth?

A team of dogs is pulling a sled with a net force of 2000 N. The sled is accelerating a 2.2 m/s^2. What is the mass of the sled?

Is the reduction of copper from copper (ii) oxide by carbon exothermic or endothermic? what is the sign of the energy change?

True or false we have mucus that covers are stomach which prevents or stomach acid from digesting or stomach

a man applies a force of 100n to a rock for 60 seconds but the rock does not move what is the amount of work done by the man on the rock

The driver of a car traveling at 32 m/s applies the brakes and undergoes a constant deceleration of 2.25 m/s^2.