Explanation:
Speed has only magnitude.
Velocity has magnitude and direction.
"A bike goes 25 m/s toward main street."
This includes a direction, so it is velocity (V).
"A person walks 4 mph."
This has only magnitude, so it is speed (S).
"A plane flies 200 m/s."
This has only magnitude, so it is speed (S).
"A bird flies 100 mph due south."
This includes a direction, so it is velocity (V).
To determine the object which could give the greatest impact we will apply the concept of momentum. The object that has the highest momentum will be the object that will impact the strongest. Our values are
Mass of Object A
Velocity of object A
Mass of object B
Velocity of object B
The general formula for momentum is the product between mass and velocity, then
For each object we have then,
Since the momentum of object A is greater than that of object B, then object A will make you feel force upon impact.
Water was confirmed to be on the sunlit surface of the Moon
Answer:
0.1 s
Explanation:
The net force on the log is F - f = ma where F = force due to winch = 2850 N, f = kinetic frictional force = μmg where μ = coefficient of kinetic friction between log and ground = 0.45, m = mass of log = 300 kg and g = acceleration due to gravity = 9.8 m/s² and a = acceleration of log
So F - f = ma
F - μmg = ma
F/m - μg = a
So, substituting the values of the variables into the equation, we have
a = F/m - μg
a = 2850 N/300 kg - 0.45 × 9.8 m/s²
a = 9.5 m/s² - 4.41 m/s²
a = 5.09 m/s²
Since acceleration, a = (v - u)/t where u = initial velocity of log = 0 m/s (since it was a rest before being pulled out of the ditch), v = final velocity of log = 0.5 m/s and t = time taken for the log to reach a speed of 0.5 m/s.
So, making t subject of the formula, we have
t = (v - u)/a
substituting the values of the variables into the equation, we have
t = (v - u)/a
t = (0.5 m/s - 0 m/s)/5.09 m/s²
t = 0.5 m/s ÷ 5.09 m/s²
t = 0.098 s
t ≅ 0.1 s
