Answer:
750W
Explanation:
40×10= 400N
work done= force × distance
=400 × 75
=30000 J
Power= work done/ time
= 30000 ÷ 40
= 750 W
You are running at constant velocity in the x direction, and based on the 2D definition of projectile motion, Vx=Vxo. In other words, your velocity in the x direction is equal to the starting velocity in the x direction. Let's say the total distance in the x direction that you run to catch your own ball is D (assuming you have actual values for Vx and D). You can then use the range equation, D= (2VoxVoy)/g, to find the initial y velocity, Voy. g is gravitational acceleration, -9.8m/s^2. Now you know how far to run (D), where you will catch the ball (xo+D), and the initial x and y velocities you should be throwing the ball at, but to find the initial velocity vector itself (x and y are only the components), you use the pythagorean theorem to solve for the hypotenuse. Because you know all three sides of the triangle, you can also solve for the angle you should throw the ball at, as that is simply arctan(y/x).
Answer:

Explanation:
For answer this we will use the law of the conservation of the angular momentum.

so:

where
is the moment of inertia of the merry-go-round,
is the initial angular velocity of the merry-go-round,
is the moment of inertia of the merry-go-round and the child together and
is the final angular velocity.
First, we will find the moment of inertia of the merry-go-round using:
I = 
I = 
I = 359.375 kg*m^2
Where
is the mass and R is the radio of the merry-go-round
Second, we will change the initial angular velocity to rad/s as:
W = 0.520*2
rad/s
W = 3.2672 rad/s
Third, we will find the moment of inertia of both after the collision:



Finally we replace all the data:

Solving for
:

The yellow star will live longer as it has less mass
Option c) 1.5 V
Explanation:
<em>As the circuit is build in series first we will find the current passing through the complete circuit. Current stays the same in each element is the series cirucuit, however, the voltage is different.</em>
Voltage is given by the following formula:
V = IR
<em>Because we have to find current through whole circuit, we will first find resistance of the whole circuit.</em>
Equivalent Resistance R(eq): R1 + R2 = 60 + 60 = 120 ohm
Current passing through whole circuit be:
= 0.025
Now we will find out the voltage between C and D:
Current stays the same in series circuit: I = 0.025 c
Resistance between C and D is, R = 60 ohm
Voltage becomes, V = IR = 0.025 * 60 = 1.5 V