Answer:
Radiation , Conduction and Convection
Explanation:
Those are the ways heat is transferred
Answer:
The distance between the helicopter and the man changing at that instant is 41.46 ft/sec.
Explanation:
Given:
Distance between the man and the helipad, = ft
Vertical distance between the helipad and the helicopter, = ft
Helicopter lift off vertically and is raising at a speed of 45 ft/sec.
That can be written as, = 45 ft/sec
Now from the diagram (attached with) we can find the hypotenuse of the triangle that is the distance between the man and the helicopter.
Applying Pythagoras theorem:
⇒
⇒
⇒
⇒ ft
Now to find the changing distance between the helicopter and the man we have to differentiate the Pythagoras theorem as dh/dt can be obtained from there.
And we know that the distance b is constant so db/dt=0.
Using chain rule and power rule of differentiation.
⇒
⇒
⇒
⇒ <em>....eliminating the common 2 </em>
⇒
⇒ Plugging the values.
⇒
⇒ ft/sec
So,
41.46 ft/sec is the distance between the helicopter and the man changing at that instant.
Answer:
A
Explanation:
When you multiply a vector by a scalar the magnitude will change but the direction will not change.
Answer: Energy stored:A spring compresses and returns
to its original shape when released.An object lifted with a pulley drops
down when the rope is released.
Energy not stored:A boat travels through water
(and air) and doesn’t move
after stopping.A box is pushed and doesn’t
move after the pushing stops.
Explanation:
We store energy in a spring when we compress it. When we release the spring, it returns to its original shape. The stored energy changes into kinetic energy. When a pulley lifts an object, the object gains stored energy. This stored energy changes to kinetic energy when the rope is released. A boat moving on water doesn’t store energy. Its kinetic energy is transformed to thermal energy because of drag. For the same reason, pushing a box on a table against friction doesn’t store energy either.