Answer:
0.572
Explanation:
First examine the force of friction at the slipping point where Ff = µsFN = µsmg.
the mass of the car is unknown,
The only force on the car that is not completely in the vertical direction is friction, so let us consider the sums of forces in the tangential and centerward directions.
First the tangential direction
∑Ft =Fft =mat
And then in the centerward direction ∑Fc =Ffc =mac =mv²t/r
Going back to our constant acceleration equations we see that v²t = v²ti +2at∆x = 2at πr/2
So going backwards and plugging in Ffc =m2atπr/ 2r =πmat
Ff = √(F2ft +F2fc)= matp √(1+π²)
µs = Ff /mg = at /g √(1+π²)=
1.70m/s/2 9.80 m/s² x√(1+π²)= 0.572
Answer:
Option (d) is correct.
Explanation:
Work done is given by :
W = Fd, where F is force and d is displacement
Unit of work done :
The SI unit of force is Newton (N) and that of displacement is meter (m). So, the unit of work done is N-m. It is call Joule. It means that the unit of work done is Joule.
Power is given by rate at which the work is done. It is given by :
P = W/t, W is work done and t is time
Unit of power:
Unit of work is Joule (J) and that of time is second (s). It means that the unit of power is Watt and it is equal to Joule/second
Hence, the correct option is (d) "The unit for work is a joule. The unit for power is a watt, which is a joule per second".
Answer:
A stone that is dropped down into an empty well
Answer:
See explanations below
Explanation:
1) KE = 1/2mv²
mass m = 0.142kg
v = 40m/s
KE = 1/2 * 0.142 * 40^2
KE = 1/2 * 0.142 * 1600
KE = 800*0.142
KE = 113.6Joules
2) KE = 1/mv^2
KE = 196
mass m = ?
velocity v = 52m/s
Substitute
196 = 1/2*m*52²
196 = 1352m
m = 196/1352
m = 0.145kg
Hence the mass of the baseball is 0.145kg
3) KE = 1/2mV^2
288 = 1/2 * 4v²
288 = 2v²\
v² = 288/2
v² = 144
v = 12m/s
The velocity of the shotput is 12m/s
