Answer:
<h3>Anything with a dark shade in color and with no reflective surface or any metal</h3>
Explanation:
In this case, a dark shirt or blanket would be a heat conductor as well as metal would be, too
Answer:
1) 0.51 seconds.
2) 1.45 m/s.
Explanation:
given, height from which cat falls = 1.3 m
we know that, s = ut +
at².
here if we consider cat moment only in downward direction,
intial velocity of cat in downward direction , u = 0.
so, time, t =
.
⇒ t =
= 0.51 seconds.
t = 0.51 seconds.
now, consider cat moment only in forward direction
s = ut , since acceleration is zero in forward direction
⇒ u =
.
so, u =
= 1.45 m/s .
Answer:
Top: PE = max, KE = 0
Middle: PE = half, KE = half
Bottom: PE = 0, KE = max
Explanation:
The potential energy of an object is the energy possessed by the object due to its location; it is given by

where
m is the mass of the object
g is the acceleration due to gravity
h is the height of the object from the ground
The kinetic energy of an object is the energy possessed by the object due to its motion; it is given by

where
v is the speed of the object
Now we analyze the three situations for the boy on the bycicle:
Top of the hill: here h (the height) is maximum, so the potential energy is maximum, while the speed is zero, therefore the kinetic energy is zero.
Middle of the hill: here h (the height) is half of the initial value, therefore the potential energy is also half of the initial potential energy. According to the law of conservation of energy, the total mechanical energy (potential+kinetic) is constant: this means that also the kinetic energy is half of the initial potential energy.
Bottom of the hill: here h is zero, therefore the potential energy is now zero. As a result, all the mechanical energy has been converted into kinetic energy, therefore the kinetic energy is maximum and it is equal to the potential energy of the boy when he was at the top.
Answer:
Maximum Height
Explanation:
The maximum height is the highest point reached by a projected body. At this point, final velocity, v of the body is equal to 0; because upward motion is at its peak and the body start to fall again.
Hence, final velocity v is always 0 at this maximum point and the direction of motion changes from upward to downward.
Final velocity at this maximum height is zero because of the directional change experied by the object and the fact that upward motion of the body terminates at this point.
Answer:
Truck will be at a distance of 720 m
Explanation:
Speed of the truck is given as 90 m/sec
Time for which truck travel t = 10 seconds
We have to find the distance that how much truck travel in 8 sec with speed of 90 m/sec
We know that distance is given by 
So distance traveled by truck in 8 sec will be equal to 
So truck will be at a distance of 720 m