A force is anything that can push or pull on an object. Forces influence objects that are at rest or that are already in motion. Isaac Newton's three laws of motion involve inertia, mass, velocity, and momentum. Key forces include gravity, friction, and magnetism.
Answer:
The steady-state theory was first proposed by Sir James Jeans in the 1920s, but it really got a boost in 1948 when it was reformulated by Fred Hoyle, Thomas Gold, and Hermann Bondi.
Explanation:
True
Answer:
3.46 seconds
Explanation:
Since the ball is moving in circular motion thus centripetal force will be acting there along the rope.
The equation for the centripetal force is as follows -
Where, 
is the mass of the ball, 
is the speed and 
is the radius of the circular path which will be equal to the length of the rope.
This centripetal force will be equal to the tension in the string and thus we can write,
and, 
Thus, 
m/s.
Now, the total length of circular path = circumference of the circle
Thus, total path length = 2πr = 2 × 3.14 × 2 = 12.56 m
Time taken to complete one revolution = 
= 
= 3.46 seconds.
Thus, the mass will complete one revolution in 3.46 seconds.
Answer:
36 km/h
Explanation:
The total velocity is the sum of the two velocities that add to the movement of the boat.
Since the wind pushes the boat at 21 km/h and the current that runs in the direction of the movent of the boat is 15 km/h, the total velocity at wich the boat moves is:
21km/h + 15 km/h = 36 km/h
Similar chemical behavior. All the members of a group of elements have the same number of valence electrons and similar chemical properties.
