Answer:
Because the gravitational attraction of the Sun hold them in motion around it
Explanation:
For an object travelling in a straight path at constant velocity, the net force acting on the object must be zero.
The planets in the Solar System, however, do not experience a zero net force: in fact, the Sun exerts a gravitational attraction on them, whose magnitude is given by

where
G is the gravitational constant
M is the mass of the Sun
m is the mass of the planet
r is the average distance between the Sun and the planet
Due to the presence of this force, the Sun makes the planets 'deviating' from their straight path, forcing them to following an elliptical path around the Sun.
Answer:
7.8 N
Explanation:
Applying,
I = Ft................. Eqaution 1
Where I = Impulse on the egg test dummy, F = Force on the egg test dummy during the time interval, t = time interval
make F the subject of the equation
F = I/t.................. Equation 2
From the question,
Given: T = -0.39 N.s, t = 0.050 s
Substitute these vales into equation 2
F = -0.39/0.050
F = -7.8 N
Hence the force that act on the egg test dummy is 7.8 N
Answer:
a

b
The value is 
Explanation:
From the question we are told that
The mass is
The spring constant is 
The instantaneous speed is 
The position consider is x = 0.750A meters from equilibrium point
Generally from the law of energy conservation we have that
The kinetic energy induced by the hammer = The energy stored in the spring
So

Here a is the amplitude of the subsequent oscillations
=> 
=> 
=> 
Generally from the law of energy conservation we have that
The kinetic energy by the hammer = The energy stored in the spring at the point considered + The kinetic energy at the considered point

=> 
=> 
I believe the answer is option A