A 13-kg sled is moving at a speed of 3.0 m/s. At which of the following speed will the sled have twice as much kinetic energy?
<span>4.2 m/s</span>
Answer:
a) -3.267 m/s
b) 2.227 m/s
Explanation:
As per the conservation of momentum
m1v1 + m2v2=0
m1= mass of log
m2 = mass of lumber jack
v1 = velocity of log
v2 = velocity of lumber jack
a) Velocity of first log
m/s
b) m1v1 + m2v2 = m3v3
Velocity of log
= 
Answer:
The magnetic flux through the desk surface is 
.
Explanation:
Given that,
Magnetic field B = 0.42 T
Angle =68°
We need to calculate the magnetic flux
Where, B = magnetic field
A = area
Put the value into the formula
Hence, The magnetic flux through the desk surface is .
Answer:
Explanation:
A )
speed of swimming in still water is given by the expression
distance / time
= 50 / 25
= 2 m /s
In lane 1 , 1.2 cm/s current is flowing in the direction that the swimmers are going so swimmers will cover distance at the rate of 2 + 1.2 = 3.2 m /s.
time to cover distance of 50 m in lane 1
= distance / speed
= 50 / 3.2 = 15.625 s
In lane 8 , 1.2 cm/s current is flowing against the direction that the swimmers are going so swimmers will cover distance at the rate of 2 - 1.2 = .8 m /s.
time to cover distance of 50 m in lane 1
= distance / speed
= 50 / .8 = 62.5 s
<span>Radius = 4.6 m
Time for one complete rotation t = 5.5 s.
Distance = 2 x 3.14 x R = 2 x 3.14 x 4.6 m = 28.888.
Velocity V = distance / time = 28.888 / 5.5 s = 5.25 m/s
Force exerted by cat Fc = mV^2 / R = (mx 5.25^2) / 4.6 m
Force of the cat Fc = 6m, m being the mass.
Normal force = Us x m x g = Us x m x 9.81 = Us9.81m
equating the both forces => Us9.81m = 6m => Us = 6 / 9.81 => Us = 0.6116
So coefficient of static friction = 0.6116</span>
