Answer:
B) A car slowing as it reaches a traffic light.
Explanation:
Newton's second law states that an object which experiences unbalanced forces has an acceleration, according to the equation:
where
F is the net force acting on the object
m is its mass
a is its acceleration
When the forces are unbalanced, it means that the net force F is different from zero, so the acceleration of the object (a) is also different from zero.
Now let's analyze each situation:
A) A box resting on a horizontal floor. --> The object is at rest, so it is not accelerating. This means that the forces acting on it are balanced (net force = 0), so this is not the correct choice
B) A car slowing as it reaches a traffic light. --> The car is slowing down, this means that it has an acceleration: therefore, it is experiencing unbalanced forces. So, this is the correct choice.
C) A car with its cruise control set to 30 km/h. --> The car is moving at constant velocity, so it has zero acceleration. This means that the forces acting on it are balanced (net force = 0), so this is not the correct choice
D) A penny at terminal velocity after falling off of a building. --> The penny is at terminal velocity, which means that it is moving at constant velocity, so it has zero acceleration. This means that the forces acting on it are balanced (net force = 0), so this is not the correct choice.
Therefore, the correct choice is
B) A car slowing as it reaches a traffic light.
Answer:
The workdone is
Explanation:
The free body diagram is shown on the first uploaded image
From the question we are given that
The force is on the force gauge
The distance that Magnus pulled the bus
Generally the workdone by the tension force on Magnus is
This negative sign show that is tension force is in the opposite direction to Magnus movement (i.e the movement of the bus )
Substituting value we have
Answer:
Explanation:
According to the newton's second law of motion we can apply F=ma hear
Force = mass * acceleration
(assume the piano is moving left side )
←F = ma
Answer:
428.59 N
Explanation:
Buoyant force, where V is volume, g is gravitational constant and \rho is density
where
is upward force
where
is the density of hippo
Using g as 9.81
Therefore, the upward force=428.59 N