Answer:
Friction produces unnecessary heat leading to the wastage of energy. The force of friction acts in the opposite direction of motion, so friction slows down the motion of moving objects. Forest fires are caused due to the friction between tree branches. However, friction can also cause problems in a car. Friction between moving engine parts increases their temperature and causes the parts to wear down. Friction can be both harmful and helpful, so it may be necessary to decrease or increase friction.
Answer:
magnetic force on falling Bar F = B*i*L*sin(90) = B*(B*L*v/R)*L = B^2*L^2*v/R
direction of the force is vertically upwards
Explanation:
Answer:
11250 seconds or 187.5 mins
Explanation:
The formula to be used here is that of speed.
Speed (in m/s) = distance (meter) ÷ time (secs)
The speed provided is 32 meters per second
The distance provided will have to be converted to meters; 360 km = 360 × 1000 = 360000 meters
Thus,
32 = 360000 ÷ time
time = 360000 ÷ 32
time = 11250 seconds or 187.5 mins
It will take Naomi 11250 seconds to get to New York
<span>when it returns to its original level after encountering air resistance, its kinetic energy is
decreased.
In fact, part of the energy has been dissipated due to the air resistance.
The mechanical energy of the ball as it starts the motion is:
</span>

<span>where K is the kinetic energy, and where there is no potential energy since we use the initial height of the ball as reference level.
If there is no air resistance, this total energy is conserved, therefore when the ball returns to its original height, the kinetic energy will still be 100 J. However, because of the presence of the air resistance, the total mechanical energy is not conserved, and part of the total energy of the ball has been dissipated through the air. Therefore, when the ball returns to its original level, the kinetic energy will be less than 100 J.</span>
Explanation:
- Mass(m)= 20kg
- Acceleration (a)= 5m/s²
- Force(F)= ?
We know that,
Hence, the needed force is 100N.