To find average speed, we divide the distance of travel (in this case, 400 metres) by the time she took, 32 seconds. Therefore: 12.5 seconds is her average speed.
Answer:
375 m.
Explanation:
From the question,
Work done by the frictional force = Kinetic energy of the object
F×d = 1/2m(v²-u²)..................... Equation 1
Where F = Force of friction, d = distance it slide before coming to rest, m = mass of the object, u = initial speed of the object, v = final speed of the object.
Make d the subject of the equation.
d = 1/2m(v²-u²)/F.................. Equation 2
Given: m = 60.0 kg, v = 0 m/s(coming to rest), u = 25 m/s, F = -50 N.
Note: If is negative because it tends to oppose the motion of the object.
Substitute into equation 2
d = 1/2(60)(0²-25²)/-50
d = 30(-625)/-50
d = -18750/-50
d = 375 m.
Hence the it will slide before coming to rest = 375 m
Answer:
5500000 millimeters
Explanation:
1 kilometre= 1000 meter
5.5 km=5.5 * 1000
=5500
Now,
1 metre = 1000 millimetres
5500 metre=1000*5500
=5500000 mm
Answer:
Explanation:
The equation for Power is
P = Work/time to do work and the equation for work is
Work = FΔx
We first need to find the amount of work done, then we can find the power it took to do that work.
W = 2000(9.8)(28) so
W = 550,000 N*m
Now we fill that into the power equation:
gives us
P = 18000 Watts. But we need kW, so we divide by 1000 to get
P = 18 kW of power.
Answer:
2 * 10^5 pa
Explanation:
Pressure = Force / Area
Each thigh bone has a cross sectional area of 10cm²
Both thigh bones :
2 * 10cm² = 20cm²
To m² : 20 * (0.01)²
20 * 0.0001 m² = 0.002 m²
Force = mass * acceleration due to gravity(g)
g = 10m/s² ;
Force = 40 * 10 = 400N
Pressure = 400 N / 0.002 m²
Pressure = 200,000 N/m² = 2 * 10^5 pascal
