Answer:2.45 m/s
Explanation:
Given
Launch velocity
launch angle
as the vertical velocity first decreasing to zero and then increases to original value so its avg is zero .



thus 

Answer: 
Explanation:
We are told both planets describe a circular orbit around the star S. So, let's approach this problem begining with the angular velocity
of the planet P1 with a period
:
(1)
Where:
is the velocity of planet P1
is the radius of the orbit of planet P1
Finding
:
(2)
(3)
(4)
On the other hand, we know the gravitational force
between the star S with mass
and the planet P1 with mass
is:
(5)
Where
is the Gravitational Constant and its value is 
In addition, the centripetal force
exerted on the planet is:
(6)
Assuming this system is in equilibrium:
(7)
Substituting (5) and (6) in (7):
(8)
Finding
:
(9)
(10)
Finally:
(11) This is the mass of the star S
Electric field lines always begin at positive charges (or at infinity) and end at negative charges (or at infinity).
One could also say that the lines we use to represent an electric field indicate the direction in which a positive test charge would initially move when released from rest.
Answer:
the previous correct answer is b
Explanation:
When the circuit is closed in the system, a current is induced that follows the lenz law, which opposes the change that is occurring and therefore the coil increases and the idicidal current in the ring must reach the maximum oppositing is the current of the coil, so quiet force is repulsion
Consequently, the previous correct answer is b
Answer:
240 Nm
Explanation:
The clockwise torque is the torque determined only by the force that makes the lever rotating clockwise: therefore, the force of 80 N on the right.
The torque produced by this force is given by:

where
F is the magnitude of the force
d is the arm
For the force of 80 N on the right,
F = 80 N
d = 3 m (distance from the pivot)
So, the clockwise moment is
