Answer:
10.86 N
Explanation:
Let the average frictional force acting on the toboggan be 'f' N.
Given:
Mass of toboggan (m) = 19.0 kg
Initial velocity (u) = 4.00 m/s
Final velocity (v) = 0 m/s
Time for which friction acts (Δt) = 7.00 s
Now, change in momentum is given as:
Now, we know that, change in momentum is equal to the impulse acting on the body. So,
Impulse is, 
Now, we know that, impulse is also given as the product of average force and the time interval for which it acts. So,
Rewriting the above equation in terms of 'f', we get:
Plug in the given values and solve for 'f'. This gives,
Therefore, the magnitude of frictional force is 
Answer:
Explanation:
R² = F₁² + F₂² + 2F₁F₂ Cosθ , R is resultant force , θ is angle between them
780² = 390² + 550² + 2 x 390 x 550 Cosθ
608400 = 152100 + 302500 + 429000 Cosθ
Cosθ = .3585
θ = 69 degree.
There are a few ways to do this- unfortunately different fields are better at it than others! Medical research is generally pretty good, some other fields likewise very good, some not as much.
Basically, though, what they do is use standadisation- they agree on the terminology, units of data, statistical measures, and so forth, that will be used in that scientific field. As much as possible, every scientist in the field uses those standards so everyone working in the field should recognise it.
For instance, in clinical trials, there is very good agreement worldwide on what the different metrics we use are- e.g. in cancer research, we usually want to know the 5-year survival rate (meaning the percentage of patients still alive 5 years after diagnosis). So anyone with the right training should be able to pick up a clinical trial report and understand what the results are and what the report is saying.
Answer:
0.5 Amperes
Explanation:
Information that we have:
Power: 
Voltage: 
and we use the equation that relates this two quantities to the Current (I):
where I is the curent, P is the Power and V is the Voltage.
we substitute the values given for the Power and the Voltage to find the current:
the Current running into the bulb is 0.5 Amperes
