Answer:
IMA = Distance of Effort/ Distance of resistance
Explanation:
M.A is the force amplification of a machine.
Ideally, a screw driver has varying diameters on two ends, the shaft and the handle, however, since the question does not provide those parameters, we will assume shaft and handle have the same diameter.
DE = 4
DR = 1
Therefore, IMA =
If diameter is given, IMA is calculated by
Area of Effort/ Area of resistance i.e. AE/AR
Answer
t = 367.77 s = 6.13 min
Explanation:
According to the law of conservation of energy:
where,
P = Electric Power of Heater = 300 W
t = time required = ?
m_g = mass of glass = 300 g = 0.3 kg
m_w = mass of water = 250 g = 0.25 kg
C_g = speicific heat of glass = 840 J/kg.°C
C_w = specific heatof water = 4184 J/kg.°C
ΔT_g = ΔT_w = Change in Temperature of Glass and water = 100°C - 15°C
ΔT_g = ΔT_w = 85°C
Therefore,
<u>t = 367.77 s = 6.13 min</u>
Answer:
Explanation:
The centripetal force acting on the car must be equal to mv²/R, where m is the mass of the car, v its speed and R the radius of the curve. Since the only force acting on the car that is in the direction of the center of the circle is the frictional force, we have by the Newton's Second Law:
But we know that:
And the normal force is given by the sum of the forces in the vertical direction:
Finally, we have:
So, the minimum value for the coefficient of friction is 0.27.