The act of using senses or tools to gather information is called "observation." In scientific method, it is very essential to have this one. Through observation, we are able to get what we wanted to get using our senses and other tools. This process is very tedious if the field that you are studying is quite complicated. Hope this Helps! PLEASE PUT BRAINLIEST!
Velocity = displacement / time
Displacement = 2.3 km
Time = 5.78 mins
Velocity = 2.3/5.78
Velocity = 0.398 to the nearest 3 significant figures
Some things travel faster than the speed of light
The car undergoes an acceleration <em>a</em> such that
(45.0 km/h)² - 0² = 2 <em>a</em> (90 m)
90 m = 0.09 km, so
(45.0 km/h)² - 0² = 2 <em>a</em> (0.09 km)
Solve for <em>a</em> :
<em>a</em> = (45.0 km/h)² / (2 (0.09 km)) = 11,250 km/h²
Ignoring friction, the net force acting on the car points in the direction of its movement (it's also pulled down by gravity, but the ground pushes back up). Newton's second law then says that the net force <em>F</em> is equal to the mass <em>m</em> times the acceleration <em>a</em>, so that
<em>F</em> = (4500 kg) (11,250 km/h²)
Recall that Newtons (N) are measured as
1 N = 1 kg • m/s²
so we should convert everything accordingly:
11,250 km/h² = (11,250 km/h²) (1000 m/km) (1/3600 h/s)² ≈ 0.868 m/s²
Then the force is
<em>F</em> = (4500 kg) (0.868 m/s²) = 3906.25 N ≈ 3900 N
