Answer:
The magnitude of the force exerted on the ball by the racquet is 94.73 N.
Explanation:
The force exerted on the ball is the following:
Where:
m: is the mass of the ball = 59 g
a: is the acceleration
The acceleration of the ball can be found with the following kinematic equation:
Where:
d: is the distance = 0.36 m
: is the final speed = 34 m/s
: is the initial speed = 0 (it start from rest)
Hence, the acceleration is:
Finally, the force is:
Therefore, the magnitude of the force exerted on the ball by the racquet is 94.73 N.
I hope it helps you!
Answer:
LED run before the batteries are depleted is 3.87 hours
Explanation:
given data
battery = 4 AA
battery is rated = 1.2V, 2550 mAh
power = 3 W
efficient = 95%
to find out
How long will the LED run before the batteries are depleted
solution
we consider here power delivered by battery is = x
so power = x × efficient
3 = x 95%
x = 3.15 W
and
voltage by 4 battery is = 4 × 1.2 = 4.8 V
so current will be = 
current = 
current = 0.6577 A
so total discharge hours = 
total discharge hours = 
time = 3.87 hours
so LED run before the batteries are depleted is 3.87 hours
I think that the angular velocity vector points at right angles to the direction in which the wheels are turning (spindle on an old fashioned record player ?) and so at right angles to the direction the bike is moving in. This contributes to the gyroscope effect on the wheels and bike and allows a rapidly rotating wheel to be more stable than a slowly rotating one. Problem for the trainee cyclist is to believe that they are actually more stable when their wheels are moving quickly. 'cos the tendency is to go slowly to start with, which makes balancing harder.
But then, most cyclists, especially youngsters, don't sit down all day analysing circular motion vectors, which may be just as well.
<span>The troposphere, because it's where the weather happens.</span>
