Answer:
D) wood rubbed against a rough surface feels hot
Explanation:
The heat is transferred from one form of energy (friction of the wood being rubbed against the surface) to another (heat energy).
<span>It can form four covalent bonds. </span>
Answer:
The work done on the sled by friction, W = - 4593.75 J
Explanation:
Given data,
The combined mass of sled and the boy, m = 75 kg
The displacement of the boy, S = 25 m
The coefficient of the friction, u = 0.25
The frictional force acting on the boy,
<em>F = u η</em>
Where,
η - is the normal force acting on the boy (mg)
Substituting the values,
F = 0.25 x 75 x 9.8
= 183.75 N
Since the direction of the frictional force is against the direction of motion
F = - 183.75 N
The work done on the sled by friction,
W = F x S
= - 183.75 x 25
= - 4593.75 J
Hence, the work done on the sled by friction, W = - 4593.75 J
Answer:
1410 Hz
Explanation:
Capacitance is reduced by 2, so the angular frequency will increase by a factor of 
.
Answer:
31.68 meters per second.
Explanation:
Speed is equals to Distance divided by Time, so, this means that speed is inversely proportional to time and directly proportional to distance.
Here, Distance is given which is 274 meters.
Time taken to cover the given distance is 8.65 seconds.
So, by putting the values of distance and time in the formula of speed we will get the top speed of Cheetah which is 31.68 meters per second.
