Answer:
We know the momentum after the collision MUST be equal to the momentum BEFORE the collision.
Momentum is a VECTOR quantity having both magnitude and direction. The first ball has momentum P =m*v = 2*4 = 8 at 90degrees. The second ball has momentum P = 1*8 = 8 at -90 or 270 degrees. They sum to zero when you perform vector addition.
Explanation:
We can find the force by using the following formula;
N = ma + mg
Fa = ma = 76 x 1.2 = 91.2
Fg = mg = 76 x 9.8 = 744.8
N = 91.2 + 744.8 = 836
So, the force is 836 N.
20/45=0.4*100= 44.4 so the answer is..................................................
Answer: 44.4%
Answer:
The average speed of the earth in its orbit is 
Explanation:
The average distance between the Earth and the Sun is
.
The average speed of the earth in its orbit can be found by the next equation :
(1)
Where r is the radius and T is the period.
In this case, the orbit of the Earth can be considered as a circle
(
) instead of an ellipse.
It takes 1 year to the Earth to make one revolution around the Sun. Therefore, its period will be 365.25 days.
Notice that to express the period in terms of seconds, the following is needed:
⇒ 
Then, equation 1 can be used:


Answer:
t=1.623 sec
Explanation:
The distance traveled before the echo is had is:

Given the speed of sound as v=345m/s, we use the speed equation to solve for t:

Hence, it takes 1.623 seconds to hear the echo.