How can eclipsing binary stars be identified?

a 75 kg man is standing at rest on ice while holding a 4kg ball. if the man throws the ball at a velocity of 3.50 m/s forward, w

AysviL [449]

Answer:

His resulting velocity will be 0.187 m/s backwards.

Explanation:

Given:

Mass of the man is, $M=75\ kg$

Mass of the ball is, $m=4\ kg$

Initial velocity of the man is, $u_m=0\ m/s(rest)$

Initial velocity of the ball is, $u_b=0\ m/s(rest)$

Final velocity of the ball is, $v_b=3.50\ m/s$

Final velocity of the man is, $v_m=?\ m/s$

In order to solve this problem, we apply law of conservation of momentum.

It states that sum of initial momentum is equal to the sum of final momentum.

Momentum is the product of mass and velocity.

Initial momentum = Initial momentum of man and ball

Initial momentum = $Mu_m+mu_b=75\times 0+4\times 0 =0\ Nm$

Final momentum = Final momentum of man and ball

Final momentum = $Mv_m+mv_b=75\times v_m+4\times 3.50 =75v_m+14$

Now, initial momentum = final momentum

$0=75v_m+14\\\\75v_m=-14\\\\v_m=\frac{-14}{75}\\\\v_m=-0.187\ m/s$

The negative sign implies backward motion of the man.

Therefore, his resulting velocity is 0.187 m/s backwards.

3 0

3 years ago

When a calcium atom forms an ion, it loses two electrons. What is the electrical charge of the calcium ion? a) −2 b) −1 c)+ 1 d)

MrRa [10]

Answer:

Option D

+2

Explanation:

We know that Calcium has 20 electrons and 20 protons. It lost two electrons, it has 20 protons, but only 18 electrons. This makes calcium a positive ion with a charge of +2.

8 0

2 years ago

A weightlifter lifted 800 Newtons to a height of 2.5 meters. What is the power output if this was

stiv31 [10]

The power required is 1.6 kW.

Answer:

Explanation:

Power is defined as the amount of work done on any object for a given time interval. In other words, power is the amount of force required to move an object in a given period of time.

Power = Work done / time taken for that work done.

Here the force is given as 800 N and the displacement is given as 2.5 m, while the time required for the displacement is given as 1.22 seconds.

So the power will be ratio of the product of force acting on the weightlifter, displacement of the weight to the time taken for that displacement.

Power = (800×2.5)/1.22 =1639 W

So the power required is 1.6 kW.

5 0

2 years ago

(SCIENCE)

mart [117]

Mean is the same thing as average, so to find this you would add all of the numbers together and divide them by the amount of numbers you added. For example, (6+9+11)/3

Median is the middle number of the list of numbers, but you have to put them in numerical order first. If there is not an exact middle, you would add the middle two together and divide by two.

Mode is the number that occurs most often within the list of numbers.

3 0

3 years ago

I’m not sure how to do this

aleksley [76]

Do what?? i know how to do a lot of things to answer but there’s nothing to answer.‍♀️

6 0

3 years ago