Answer:
The speed of the plane relative to the ground is 300.79 km/h.
Explanation:
Given that,
Speed of wind = 75.0 km/hr
Speed of plane relative to the air = 310 km/hr
Suppose, determine the speed of the plane relative to the ground
We need to calculate the angle
Using formula of angle

Where, v'=speed of wind
v= speed of plane
Put the value into the formula



We need to calculate the resultant speed
Using formula of resultant speed

Put the value into the formula



Hence, The speed of the plane relative to the ground is 300.79 km/h.
Charge on can A is positive.
Charge on can C is negative.
Punctuation and capitalization are very useful things to pay attention to and this question would be a lot easier to understand if you had actually used both capitalization and punctuation. If I'm understanding the question, you have 3 metal can that are insulated from the environment and initially touching each other in a straight line. Then a negatively charged balloon is brought near, but not touching one of the cans in that line of cans. While the balloon is near, the middle can is removed. Then you want to know the charge on the can that was nearest the balloon and the charge on the can that was furthermost from the balloon.
As the balloon is brought near to can a, the negative charge on the balloon repels some of the electrons from can a (like charges repel). Some of those electrons will flow to can b and in turn flow to can c. Basically you'll have a charge gradient that's most positive on that part of the can that's closest to the balloon, and most negative on the part of the cans that's furthest from the balloon. You then remove can B which causes cans A and C to be electrically isolated from each other and prevents the flow of elections to equalize the charges on cans A and C when the balloon is removed. So you're left with a deficiency of electrons on can A, so can A will have a positive overall charge, and an excess of electrons on can C, so can C will have a negative overall charge.
Answer:
The car strikes the tree with a final speed of 4.165 m/s
The acceleration need to be of -5.19 m/seg2 to avoid collision by 0.5m
Explanation:
First we need to calculate the initial speed 
Once we have the initial speed, we can isolate the final speed from following equation:
Then we can calculate the aceleration where the car stops 0.5 m before striking the tree.
To do that, we replace 62 m in the first formula, as follows:

Answer:
KE= 1/2mv²
Explanation:
The kinetic energy of a body is the energy possessed by virtue of the body in motion
Given the parameters
m which is the mass of the body
v which is the velocity of the body too
K.E = kinetic energy
The expression for the kinetic energy of a body is given as
KE= 1/2mv²
The change in horizontal velocity is (4.7 - 8.1) = -3.4 m/s
The change in vertical velocity is (3.2 + 3.3) = 6.5 m/s
These are the components of velocity DELIVERED to the ball by the player's pretty head during the collision.
The magnitude of the change in velocity is √(-3.4² + 6.5²) = 7.336 m/s .
The magnitude of the ball's change in momentum is (m · v) = (0.44 · 7.336) = 3.228 kg-m/s .
==> The change in the ball's momentum is exactly the <em>impulse</em> during the collision. . . . . . <em>3.228 kg-m/s</em> .
==> The direction of the impulse is the direction of the change in momentum: (-3.4)i + (6.5)j
The direction is arctan (6.5 / -3.4) = -62.39°
That's clockwise from the +x axis, which is roughly "southeast". The question wants it counterclockwise from the +x axis. That's (360-62.39) =
<em>Direction of the impulse = 297.61°</em>
<em></em>
We know that impulse is equivalent to the <u>change in momentum</u>, and that's how I approached the solution. Impulse is also (<u>force x time</u>) during the collision. We're given the time in contact, but I didn't need to use it. I guess I would have needed to use it if we were interested in the FORCE she exerted on the ball with her head, but we didn't need to find that.