Answer:
1.23 m/s²
Explanation:
Given:
v₀ = 0 m/s
v = 11.1 m/s
t = 9 s
Find: a
Equation:
v = at + v₀
Plug in:
11.1 m/s = a (9 s) + 0 m/s
a = 1.23 m/s²
The runner's acceleration is 1.23 m/s².
To determine the Force it is necessary that Samantha starts from the consideration of the dynamic balance between the forces acting on the car. For this, the centripetal force must be equal to the friction force (otherwise the car would lose contact with the ground), the expression of these two forces would be


Here,
= Coefficient of kinematic friction
m = mass
g = Acceleration due to gravity
v = Velocity
r = Radius
From this relationship then she should assume the following
1) The car travels at a constant speed
2) There is indeed that frictional force between the car and the road
3) There is no loss of mass during displacement
4) The centripetal force must be equal to the frictional force so that the car does not lose contact or slip
5) The radius must be constant
Answer:
The mechanical energy of the helicopter is
.
Explanation:
It is given that,
Mass of the helicopter, m = 3250 kg
Speed of the helicopter, v = 56.9 m/s
Position of the helicopter, h = 185 m
The energy possessed by an object due to its motion is called its kinetic energy. It is given by :


The energy possessed by an object due to its position is called its potential energy. It is given by :


The sum of kinetic and potential energy is called mechanical energy of the system. It is given by :


or

So, the mechanical energy of the helicopter is
. Hence, this is the required solution.
Answer:
The gravitational pull is determined by the mass and distance.
Explanation:
According to Newton's law of universal gravitation

where F is the gravitational pull, G is gravitational constant, m₁ and m₂ are masses of bodies and r is the distance between them.
It can be seen from the above equation that F is directly proportional to the product of the masses and inversely proportional to the square of distance between them.
F ∝ m₁m₂
F ∝ 1/r²
The answer is (A) the object must be at rest.
When all of the forces acting on an object balance, the net force is zero and hence the object will not move.
Yes, the direction might also change under some special circumstances.