Answer and Explanation:
The estimation of the mass of the objects is as follows
Given that
The mass of an apple is about 100 g
Just like that, we do some estimation of different objects
A dime is around 1 g
A smartphone is about 100 g
An adult male is approx 100 kg
A college physics textbook is around 1 kg
A ripe banana is around 100 g
A small car is around 1,000 kg
Yes the Earth is bigger than the Moon.
The moon is one-quarter the size of Earth.
Answer:
Explanation:
In the four hours before 13:00 the train traveled 4(80) = 320 km.
It needs to travel another 4(320) = 1280 km in the next 21:00 - 13:00 = 8 hrs.
1280 / 8 = 160 km/hr
N<span>o net external force acts on the system </span>
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