Answer:
Explanation:
It is given that,
Mass of the car, m = 763 kg
Speed of the car, v = 26 m/s
Mass of the iron, m' = 15 kg
Specific heat of iron, c = 450 J/kg
When the car is in motion, it will possess kinetic energy. It is given by :
K = 257894 J
Since, energy is absorbed by the brakes. The kinetic energy of the car is absorbed by the brakes. So,
is the increase in temperature of the brakes
So, the increase in temperature of the brakes is 38.20 degrees Celsius. Hence, this is the required solution.
Answer:
The least efficient light bulb is the first one (25 W - 210 Lumen)
Explanation:
Efficiency can be defined as what you want to obtain over what you need to produce it. In this case Eff= Wattage / Lumen. For each light bulb, their efficiency is: 8.4 / 11.12 / 15.7 Lum/W
Answer:
The average speed of the bus, v = 1.55 m/s
Explanation:
Given that,
Number of blocks traveled by bus towards east = 6
Number of blocks traveled by bus towards north = 8
Length of each block = 100 m
Distance traveled by bus towards east 6 x 100 = 600 m
Distance traveled by bus towards north 8 x 100 = 800 m
The total distance traveled, d = 600 + 800 = 1400
Time taken by the bus to travel is, t = 15 minutes
The velocity is given by the formula
v = d/t m
Substituting the values in the above equation
v = 1400 m /(15 x 60) s
= 1.55 m/s
Hence, the average speed of the bus, v = 1.55 m/s
Answer:
Explanation:
An impulse results in a change of momentum.
The impulse is the product of a force and a distance. This will be represented by the area under the curve
a) W = ½(4.00)(3.00) = 6.00 J
b) W = (11.0 - 4.00)(3.00) = 21.0 J
c) W = ½(17.0 - 11.0)(3.00) = 9.00 J
d) ASSUMING the speed at x = 0 is in the direction of applied force
½(3.00)(v₄²) = ½(3.00)(0.450²) + 6.00
v₄ = 2.05 m/s
½(3.00)(v₁₇²) = ½(3.00)(0.450²) + 6.00 + 21.0 + 9.00
v₁₇ = 4.92 m/s
If the initial speed is NOT in the direction of applied force, the final speed will be slightly less in both cases.
