Answer:
Explanation:
The equation for this, since we are talking about weight on an elevator, is Newton's 2nd Law adjusted to fit our needs:
where the Normal Force needed to lift that elevator car is the tension. So the equation then becomes
T = ma + w where T is the tension in the cable to lift the elevator, m is the mass of the elevator (which we have to solve for), a is the acceleration of the elevator (positive since it's going up), and w is the weight of the elevator (which we have as 5500 N). Solving first for mass:
w = mg and
5500 =- m(10) so
m = 550 kg. Now we have what we need to solve for the tension:
T = 550(4.0) + 5500 and
T = 2200 + 5500 so
T = 7700 N
Answer:
The initial mass of the rocket is 526.2 kg.
Explanation:
Given that,
Final speed = 105 m/s
Time = 18.0 s
Exhaust initial speed = 1200 m/s
Mass of burned fuel = 110 kg
We need to calculate the initial mass
The velocity change of rocket under gravity is defined as,
....(I)
We know that,
Put the value of m in equation (I)
Hence, The initial mass of the rocket is 526.2 kg.
Annual salary(2012) = $70,000
Annual inflation = 7%
Therefore, the salary you need to earn in 2020 in order to have the same purchasing power can be calculated below
where
n = 8
r = 7/100 = 0.07
PV = 70, 000
The salary you need to earn in 2020 to have the same purchasing power = $120, 273.03