Answer:
F=30N
a= 3m/s^2
m=?
F=ma
30=m(3)
30/3=m
m=10kg
The mass of the ball is 10kg
To find out how much work he has done, we must first calculate force using the force formula (F= Mass*Acceleration). In this case, mass is 79.4 and acceleration is the gravitational constant of 9.8m/s, plugging this into the formula we find that force is 778.12Newtons. Next, we need to multiply force by the distance to get the amount of energy used to lift his partner once. Which is 778.12 * .945 = 735.32. Finally, we need to multiply 735.32 by the number of times he lifts his partner, 33, to get 735.32 * 33 to find that the energy he has expended 24,265.56 Joules of energy.
Answer:
Less than a quarter of Earth's surfaces are dry, ice free lands
John used smothering as the method to control the harmful invasive plants in his orchard. Smothering is an example of a manual method of control and it works best in a small population of invasive species. Smothering involves covering the invasive species with a barrier that is highly impenetrable for one growing season in order to prevent these species from thriving in the environment.
The purpose of an experiment is to LEARN the EFFECT of something.
The way you do that is to CHANGE the thing and see what happens.
You can change as many things as you want to. But If you change
TWO things and observe the result, then you don't know which one
of them caused the effect you see.
Or maybe BOTH of them working together caused it. You don't know.
So your experiment is not really much good. You need to do it again.